As others have said, it's not a problem with the CPU. I think the problem is in the power section from something being shorted - possibly killing something around there - Maybe the MXL7704. You could try to check pin 1 of the GPIO (the two rows of pins - 40 in total) to check whether it has 3.3v, if it doesn't, then this could be a blown MXL7704 (the square chip near the power connection) which is a DCDC step down convertor that gives the 3.3v. The SD card needs 3.3v so might explain why the system boots, but the SD card wont read? You can check the MXL7704 also - Pin7 is Vin, Pin24 should be 5v, pin1 is VDDIO, which should be 3.3v. Go on - spend a few more days on it :D
Also getting psu components from ebay/amazon is like asking problems. usually relabeled same series variant that can't deliver max current or components that have failed production tests.
Hey vince, as far as i know you can get the raspberry schematics online. You could look up all the different power lines and maybe find the faulty ic or component.
I utterly despise the MXL7704 PMIC, it's incredibly easy to kill for a board that's meant to be tinkered with, and they're not even a "generic" part you can buy for all boards! I had a Pi 3B+ too and it just randomly quit working one day, no more 3.3v. I can only guess ESD was at fault.
Broke an Arduino Uno sliping on IO shield shorting a pin to ground. Only the voltage regulator was blown so it was an easy fix. But yeah it is really easy to slip and it is unforgiving!
This is why I am a huge fan of this channel, subscriber and a proud Patreon. Nobody would go the extra mile like you do. Thanks for another hour of entertainment!
Exactly this! The amount of other repair RUclipsrs that would say “it’s not economically viable to fix” if it can be fixed then fix it, that’s the whole point.
I agree. thats also what I love about these Videos. Vince teasing us (oh I think this cant be fixed) and then the video goes on for another hour and he tries everything :D... I'm the same though I'm soo stubborn when something is not working I either fix it or repair it till it turns to ashes.
Great video Vince!!! I think its a power management issue - CPU when doing "more" at the install part is not getting enough power. I would have a look back at replacing that power management IC and see if there's any other IC that works "with it". Was great to see how the larger RAM was "just detected"! I might have a go at upgrading the RAM on one of mine!
Thanks Vince, i have played with Raspberry Pi's when they first came out. I did the slip thing also when pushing a wire onto one of the pins that i had connected to some item that i was tinkering with. Ended up taking out the 3.3v . You have motivated me to pull that Pi out and do some testing on it like you showed us, so thanks again Vince for your videos. Cheers from down under....
I’m 56, when i was 15 I was wiring up projects with transistors , resistors etc. I would have given my eye teeth to have something like the raspberry Pi. I put a Sinclair spectrum together with a QL and wired them together so I could send messages to mum in the living room. Early network I think. :-)
I think an Arduino kit might be of more interest to you. Are you still keen on tinkering? I happen to be almost that age too. I use my Raspberry Pi (3B+) to control 2 3D printers through my home network.
@@TechGorilla1987 pico Pi, if you to the simplified, flashing led on and off, and build a first simple little board, and any of computer lying around, programming is as simple as copying, file to USB flash drive,
Great effort, and great video 👍I've got a dedicated room, but that is full of boxes too!😂😂😂 Low melt solder is great stuff 🙂Yes Digikey postage is quite expensive. I usually wait until I need a few parts for a few different items before I order to get free postage. If you search raspberry pi 4 schematic there is a partial schematic of the power supply section which might be useful. Bit of a co-incidence I recently bought an "untested" Pi setup with keyboard and case, which was posted a couple of days ago...
You are very clever to get some of things repaired on the show. I enjoy watching it. you’re very lucky to get some of it all fixed and repaired. I hope you’re making good profit out of this when you fix these things that you show on your show because I enjoy watching it all the time.
Hi Vince, are you sure all voltages are okay? Maybe there is some voltage rail Missing top bring the pi to full live?! If you search in the web for the schematics there is at least a reduced one available showing the two voltage regulators with all the rails (TP 4 - 3.3V / TP11 3.3V / TP13 1.8V / TP14 1.1V / TP15 VDD Core ?V / TP34 1V) I don't believe that the CPU is the problem here - low impedance readings in cores are actually a normal think and arent every time an Indikator for a blown chip (and in your video we can see that it is enough alive to give us a picture :)). Love your videos thanks for doing these repairs :)!
The problem is more likely in the power section. It is not booting correctly because not all rails are up - or the rail you used for jury rigging can not deliver enough amps. With defective RAM or CPU, it wouldn't boot at all. Do not use a power bank for working with the PIs - the PIs need at least as 1.5A supply - better 3A- and most power banks only deliver 1A over USB-A. You can see the power bank cutting out multiple times - every times it does it, it could not deliver the needed current. You tried supplying the CPU with the bench supply - but can it really deliver 5-10A at 0,8V ... because that's what the CPU needs as peak values. And the power supply, does not look like it could supply 10A. PS: @heinrichfelder1849 provided a list of the rails with voltage and corresponding testpoints in one of the commets. PSS: The "apparent" problems with the RAM, are likely because you used the RAM power rail to power the CPU with the hack. And it can not deliver enough power for the CPU - especially since it is too high for the CPU.
Vince, I’m confused why you didn’t look at the full schematics and mechanical drawings for the board on the Pi website? I know you like a challenge but as they provide huge quantities of documentation it is good to make use of it as it would be the sort of thing the right-to-repair campaigners are pushing other companies to provide. Just a thought. 😀👍
I was screaming this. FFS, it's open source hardware, you don't have to guess anything! A bit like cod3r recently injecting 12V onto a 3.3V smoke release pin when a simple search would have shown what a 1117 3.3 does. All seems to be becoming a bit electroboom but without the monobrow.
@@georgeprout42 It is not open source hardware ... to be exact: The Raspberry PI firm is about to do an IPO an be listed at the London stock exchange. There are only limited schematics available, not full schematics.
@@TylerDurden-pk5km Don't be pedantic you know what the guy was getting at as well as I do. To not use any info on something if it's right in front of you is a bit daft.
@@andymouse It is not pedantic - the hardware information provided by the raspberry pi foundation is indeed limited. And that's because they have NDAs with Broadcom and under der foundation is a commercial company that does not want to see it's hardware cloned - because they want to make money.
Yeah, although the schematics are incomplete (no SoC section due to Broadcom NDAs), they do list the power section with the PMIC (which was blown here) as well as the power rails. Could have saved Vince many weeks of struggling.
Dunno m8. If the CPU was blown or the memory cooked, it wouldnt run the bootloader (the text screen) nor the RPi OS installer shim where you can push shift and have it download files etc. That requires a fair bit of cpu/memory/peripherals interfacing. I fear the SD-card bit is gone? Tried a USB memory stick? What a tough journey. There should be schematics on raspberry pi's right? The whole idea is it is open source hardware? Thanks for another great video, i do respect the work you put in!!
There are limited schematics...but I think you may be right it all seems to be running fine, I suspect the power supply is messed up and there is no 3.3v, which is needed for the SD card. The USB memory stick is a good shout as the usb all seems to be working!
@devttyUSB0 you seem to be mixing up software and hardware. Schematics are about the hardware. And, as for the software part, the raspberry pi firmware is NOT open-source. (And it has never been)
Hi Vince, could you tell me what settings you use on your thermal camera please and whether you have a lens over it? I have a HIKMICRO model, not as good as yours, but I’d imagine they all have similar settings. Thanks
I'd like to know about that microscope station you're using there. That would come in handy for a lot of projects I could do. What brand / model is yours and how well do you like it?
Not sure if it matters, but at 50:36 you can see that your jumper wire laterally pushed the component next to the RAM chip you were installing. Excellent video, as always. 🤌
Hi Vince, if I remember correctly, the Raspberry Pi needs a supply of up to 3amps at times. I bought power supplies for the sole purpose of powering them up. Your USB power brick is probably current limited to about 2 Amps. Try a variable current load on the power brick to see what the max it can deliver. If you get the Pi to boot up at all, it's pretty safe to say the CPU is working, and you probably have some RAM working, too. My guess is you are missing a power rail somewhere on the board. Get the schematics and test for all the power rails. Power rails are always the first place to look. Another tool you are not using is your scope. You compare resistance and voltages, but not waveforms on a scope. Scopes will also show you if power rails have noise or in the case of you linking two points if there are data signals on those points or just power rails. Also, you "might" need different image files to boot the various Pi's not just the latest version, I'm not sure. Good video, Vince. Get the schematics and go from there. Thanks.
the da9121 talks to the SOC (cpu) so I assume that is for power delivery ( can change the output voltage as required) for the SOC (System on Chip) so if that chip is faulty (da9121) or (SOC) could cause the the system to halt
@6:17 you can see the conformal coating still on the board between bga points, at 6:24 you see that it was removed. While they are connected it could cause the chip to not sit correct. You may want to put some conformal coating between those points to make sure the chip sits down correctly.l
Someone else may have already noticed this, but the one that registered a red light when plugged in… I think when you installed the RAM at 50:37, you can see the heatsink on the neighboring chip wiggle. I wonder if the chip underneath moved?
I also noticed the same thing. I highly doubt this was an issue. I have the 8GB model and it came with heatsinks for me to install. The glue on them wasn't very strong and I could twist them by hand without causing any damage. The hot air likely softened the adhesive, causing it to shift slightly. I would assume that heatsink is similar to mine.
Got a bit o' quality on da hand hinge m8, my very modded top drawer Seiko 4R35 with the barbed wire carved shroud on a super heavy Tuna case, I could not sleep one morning and it had sat on my desk under cover for a long long time so I thought right... load up a video and went at it in record time, fitted a set of genuine fishbone hands plus a trident second hand, thoroughly cleansed and polished inside and out, put together and finished regulating it today with 1 sec loss dial up and 9 secs loss dial down... I can live with that accuracy :D Tomorrow if screwdrivers are willing, I am going to finish off my Alba Manta Ray which is a rare rare version of the Seiko Samurai and all going well I got a 7019 Seiko Orbit to reassemble which is a lot o' class :D See, from that very first video of yours I watched I am now becoming a bit OK at doing this over the years, you helped me through 5 weeks of hell after my triple bypass and carried on becoming better at it all... cheers m8 (although daughters might say something else as I have turned my humble flat into a massive watch repair and storage facility in amongst my live steam engines, my 1958 and 1985 Lambretta and Vespa in the front room, stacked high games consoles and even higher piles of games.... thems is not happy daughters but I don't care, fixing is fun!)(btw check out Aliexpress for portable airbrush kits, I bought one for £15 came with two airbrushes, tanks, curly air hoses, little 5v air compressor and its bloody marvellous, done already couple dials and finish is superb)
Really enjoyed this video. Just reading some of the comments about the SD reader voltage from knowledgeable people and I'm thinking there may be a Pt. 2. :)
Also, those PMIC chips (MXL7704 in older revisions of RPi 4 and DA9090/DA9121 in newer ones) seems to be programmable via i2c bus, so you may need to set correct config register values for it to function properly. Those registers, among others, control output voltages, mode of operation, and feedback signals. Something you definitely need to configure for it to communicate correctly with other parts of the board. I would guess those power failure types A and B errors refer to first (DA9090) and second (DA9121) PMICs on dual-PMIC boards.
I agree with the comments. Just want to add, those 5v powerbanks are not rated for 5.1V 2.5A in reality with stable output. Rather, they allow voltage drop on the rail and the ripple and spike would be quite unpleasant in the 2A range.
Hi vince I was just watching a video of when you attempted to fix a jbl go 2 on a amazon return video and instead of buying the chip couldn't you add one of thoes charging boards you used to charge the battery and find the plus and minus on the usbc port on the speaker so it would still charge and work like normal just with a secondary charger Circuit
My fingers have never been "precision" so I adopted coating the probes with orange nail polish and use acetone on a cloth to expose only the point. Saved me from disaster many times when I slip with the probe.
Curious Marc uses some probes that are so very micro that it's amazing. It's like your idea of a probe, but it's as thin as a hat pin or sewing needle - and just as sharp. He once sent me a link and I cannot bring it to hand right now.
Great video I am glad you got the pi 3 working, Those little Pi computers are super fun to mess with. I have that same wireless keyboard touch-pad combo it is fantastic for testing computers!
I think the small chip you tried at the start isn't soldered correctly if the CPU was blown it wouldn't do anything, when you soldered it the first time it looks like you scrapped of some solder mask and i'm not sure if the BGA balls would sit correctly without fixing the solder mask Edit: or you bought faulty chips?
I believe you’ve miscounted flashes. It seems like it is actually 4 long and 7 short flashes, and for RPi 4 that means Power Failure Type B (whatever that means). 8 flashes for SDRAM issues is for RPi 3 and earlier models.
@@sdjmchattie I’m kinda lost which one was which, but there’s no 4-8 blink code for RPi 4, so it seems unlikely :) Anyway, those PMIC chips need a bit of programming to work and communicate correctly. There’s a thread on RPi forum (which I can’t link because RUclips being RUclips) discussing same problem not booting from SD card after replacing a fried PMIC chip. It is for older board revision, but I guess newer ones also require configuration.
@@p0fs no but there is 4 long to indicate it can’t read the SD contents, and there’s an 8 short flashes without long flashes before it error code for faulty RAM. So it could be two things being reported that look like they could be one long code.
@@sdjmchattie the patterns are different for RPi3 and below and RPi 4. The former uses just a certain amount of blinks (1 to 8 if I remember correctly), while the latter uses combination of long and short blinks (category and sub code). They can’t report multiple errors at once, just the one it has stuck on (like, final BIOS post code the system freezes on)
Maybe I missed the explanation, but I didn't really get the 1V trick. Why did it work? How did you know it would be worth trying? And why did you inject it at this place?
He replaced a failed rail with another one that was working with a similar voltage. But likely the other rail, can not deliver the current the CPU needs.
Hey Vince, I'm a new 3d printer and I have the ender 3 v3 ke. One tip, make sure it's stable because they have a tendency to shake when printing. May not be an issue with the pro but from my understanding it's all of them. Open it up it's fun!
Hi Vince, just a note to say if he put too much voltage to pin 1 of the GPIO pins i believe power comes in to the board via a different route, would also be a good place to input your bench power supply, I've had multiple PIs running various things including a model delorean so have some idea of how they work
I laughed when the probe slipped. Ive done it so many times over the years. My mate used to call me passion fingers, because he said everything I touched I f*cked! Hahaha
Hi, i stumbled across this video trying to find info to help repair my broken Pi. just watched the whole video and well done for keeping going. The only other similar videos I could find where by "MadeDoctor", first one of his I found a while ago was upgrading a Pi4 2GB with 8GB. He has since done a few more. I have a Pi4 that was working fine, but after connecting it to a know working Mausberry 2A Car Pi PSU and hard resetting it a couple of times, it now only has a Red LED. +5v on the 5v GPIO pin, but no 3.3v on the 3.3v pins, whih as others have suggested means a damaged PMIC.
From the look of it, that's 4 flashes and 7 quick flashes. According to some forums it's apparently an issue with a badly imaged sd card /sd card damage. It could be that the sd card made for the 2gb is not compatible and needs to be redone specifically for the 8gb model, or could try booting off a regular usb. Might be useful info, might be pointless, but just wanted to mention it.
I reccomend building one of the ikea lack enclosures that prusa designed. It will work gread for the ender 3 and helps control temps, not just for higher temp materials but also protects all prints from gusts of cold and what have you. If you are interested in more 3d printer shit, i actually have a prusa mk3s einsy control board, it was working great until i had to catch my printer. I caught the printer by the bed and it moved quite fast so i believe i blew a trinamic driver on the board.
@1:27 - I just purchased the SKR Mini E3 v3.0 and the TFT35 touch screen to upgrade my Ender 3 (OG.) I really wanted the silent steppers. My wife was thrilled with a pair of rubber ducks. Those who know, know.
i was watching another video completely unrelated to this one(ps5 repair) but they were saying that they really had to clean the flux from under one of the chips otherwise it might not work properly perhaps deep clean the chip you replaced?
Hey, Vince. Great video. As always. Have you tried supplying power to the Raspberry via the pin strip and thereby bypassing the USB port? Pin 2 and 4 are 5v, pin 6 is GND. Would be an idea.
what I would suggest Vince, as you fix lots of usb stuff, is to buy yourself a switch that you put on the positive lind in, then there isn't a completed circuit until you press the power, but making sure not to touch ground with the probe until you are ready with the probe that is in circuit. then the ground probe and the switch is pressed at the same time that way there is less chance of shorting the circuit. accidents will still happen, but less common than a live circuit. just a suggestion. or maybe getting a pedal or something that you can use with your foot to activate the positive line in, or even going back to early electronics was a door mat buzzer system of creating your own switch, be an idea for another video maybe.
RPis have quite a capable GPU in them, easily able to decode 1080p. However the codec has to be right, and it can be tricky to convince the browser to make use of it. You have to force RUclips to serve videos in h264 codec and check that the GPU is recognized and hardware acceleration enabled. Browsers have spotty hardware acceleration support but on higher power computers people just don't notice as the CPU decoder is fast enough.
Any console videos coming soon Vince? I subscribed back in the day when you were trying to fix all the Xbox one consoles and I absolutely loved it! Would be great to see some more.
Hey Vince, I'm not sure if the PI 4 is the same as the PI 3 in regards to microSD card compatibility. I know for the PI 3 there was a list of cards known to work and some that are known to not work. I think that the 128GB might be incompatible. If you try a smaller one like a 32GB it might work.
Qual é o substituto do DA9090? Obs: Possuo um Raspberry pi 3b+ com o DA9090, ele esquenta muito e tinha curto na placa. Removi e acabou o curto, mas só acho o: mxl7704 r3 para comprar. Será que serve?
Just commenting to mention that I find the "journey" part of the repair videos more compelling than the result. Regardless of whether you're ultimately successful the video is entertaining and sometimes informative anyway.
As for Raspberry Pi there is a power requirement which 5v 2.5 amp or higher anything less it either won't turn on or act strange as I dealt with one a few years back. Using a battery power bank won't cut it why it only output 2.1 amp
I was so hoping you would be able to get the one that was over-volted to work. I have a RPI 1 that I shorted the 5v GPIO pin to ground by accident and now the memory chip itself gets very hot. I'm just not sure if I want to invest the money and time into fixing it. I bought the RPI-1 used on e-Bay for 20 dollars (US) and the memory chip on Alli-express is 10 dollars plus shipping? It would be cool to fix it but I just do not know if it is worth it money wise. As always really enjoyed the video.
Amazing video like always ❤️ Might be the MXL in more mxl7704-p4 ( he do the usb side , think feeding sd card … ) and the DA9121 ( feeding the CPU , Ram )
The CPU and RAM is fine since the bootloader works fine. You would not boot at all with broken RAM or CPU. You even download (to RAM) during network install but when it tries to write to SD card it crashes. I would check power to SD-reader part. Also make sure you have a proper power supply. The flickering green led could be a power issue. Raspberry PIs can draw quite some current. They recommend a 3A usb charger.
Vince there is a TVR diode SMBJ5.0A-TR which shorts when there is an over-voltage condition. You can either replace it cheaply or remove it altogether and it should work just fine.
You should check the voltage rails on the test points via the schematic. It looks like some supply failed. I don' think it's either the CPU or RAM. Probably some power-management chip has failed.
CPU is fine. The problem could be power management after the pre-boot environment. That chip you damaged is either part of that circuit or it damaged that circuit when it failed. The fact that it won't initialise without the 1 volt feed to the coils shows it needs that circuit to be present. The voltage of this circuit may step up or down depending on the state of the logic during booting, and hard wiring a static voltage to that point will only suffice to take it through the initial pre-boot stage where it needs to be 1 volt. Hope that makes sense. Also as @simonmilbourne8341 says - check your 3.3v on the GPIO if that is missing it wont be able to access the SD card to install software or read from it. This would be another indicator of a power management problem.
Vince your repair skills far surpass mine, but I've been a 3d printer hobbyist for years. I think you'll take to it like a duck to water once you find the space to get it set up. My "light bulb" moment was watching Thomas Sanladerer's dolly video series where he built a prusa mk2 clone from scratch using aliexpress parts.
hi i am new to your channel. have u tried booting from the USB ports to a external hard disk i heard its possible love this video i learned a lot about electronics from this video thanks :)
The last bit tell a lot. It seems like the SD card has lost it's power. Installation image is small enough to fit in ram. It just failed to communicate with SD card. Check if SD Card got 3.3volt on pin no4 from the cutout angle.
Wow Vince you’re like a dog with a bone, I really enjoyed the nice long video I’m sure there’s info on these faults out there and maybe in the future comments don’t be disheartened you did what you can 😊
Pi 3 or earlier you could power with anything. From pi 4 onwards the best thing to do is use the specific power supply. I would not be surprised if they both work with the correct power supply.
Thank you, Spoiler, this was very entertaining and more like my own projects, not that I'm close to tinkering with a pie but a failure is an opportunity to learn for future success!
You need to unbox your Ender 3 Pro! If it's the same one I'm thinking of (the S1 Pro) that is the one I will be upgrading my V2 Neo with this week when I get paid.
you can also use the raspberry pi with your ender 3d printer with a program called octoprint for remote printing, theres loads of vids on youtube about it. i have a ender 3 neo and am looking into doing this for myself hope this helps
Man I crossed the wrong pins trying to jump a brand new Mobo once. Sparks flew and the PSU tripped. PSU saved the day and everything still worked thankfully.
![I.N "HALLUCINATION" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/n5B5q1Hwt_U/mqdefault.jpg)
As others have said, it's not a problem with the CPU. I think the problem is in the power section from something being shorted - possibly killing something around there - Maybe the MXL7704. You could try to check pin 1 of the GPIO (the two rows of pins - 40 in total) to check whether it has 3.3v, if it doesn't, then this could be a blown MXL7704 (the square chip near the power connection) which is a DCDC step down convertor that gives the 3.3v. The SD card needs 3.3v so might explain why the system boots, but the SD card wont read? You can check the MXL7704 also - Pin7 is Vin, Pin24 should be 5v, pin1 is VDDIO, which should be 3.3v. Go on - spend a few more days on it :D
I have to agree i think it’s down to Psu issues. Go on have another go.
@@digihorse6730 you need to add flux when soldering bga chips in place.
Also getting psu components from ebay/amazon is like asking problems. usually relabeled same series variant that can't deliver max current or components that have failed production tests.
Hey vince, as far as i know you can get the raspberry schematics online. You could look up all the different power lines and maybe find the faulty ic or component.
I utterly despise the MXL7704 PMIC, it's incredibly easy to kill for a board that's meant to be tinkered with, and they're not even a "generic" part you can buy for all boards!
I had a Pi 3B+ too and it just randomly quit working one day, no more 3.3v. I can only guess ESD was at fault.
I think that everyone that works on electronics has done the same slip Vince, great you show it mate. Thanks
Broke an Arduino Uno sliping on IO shield shorting a pin to ground. Only the voltage regulator was blown so it was an easy fix. But yeah it is really easy to slip and it is unforgiving!
This is why I am a huge fan of this channel, subscriber and a proud Patreon. Nobody would go the extra mile like you do. Thanks for another hour of entertainment!
Exactly this! The amount of other repair RUclipsrs that would say “it’s not economically viable to fix” if it can be fixed then fix it, that’s the whole point.
I agree. thats also what I love about these Videos. Vince teasing us (oh I think this cant be fixed) and then the video goes on for another hour and he tries everything :D...
I'm the same though I'm soo stubborn when something is not working I either fix it or repair it till it turns to ashes.
Great video Vince!!! I think its a power management issue - CPU when doing "more" at the install part is not getting enough power. I would have a look back at replacing that power management IC and see if there's any other IC that works "with it". Was great to see how the larger RAM was "just detected"! I might have a go at upgrading the RAM on one of mine!
Thanks Vince, i have played with Raspberry Pi's when they first came out. I did the slip thing also when pushing a wire onto one of the pins that i had connected to some item that i was tinkering with. Ended up taking out the 3.3v . You have motivated me to pull that Pi out and do some testing on it like you showed us, so thanks again Vince for your videos. Cheers from down under....
I’m 56, when i was 15 I was wiring up projects with transistors , resistors etc. I would have given my eye teeth to have something like the raspberry Pi. I put a Sinclair spectrum together with a QL and wired them together so I could send messages to mum in the living room. Early network I think. :-)
I think an Arduino kit might be of more interest to you. Are you still keen on tinkering? I happen to be almost that age too. I use my Raspberry Pi (3B+) to control 2 3D printers through my home network.
@@TechGorilla1987 pico Pi, if you to the simplified, flashing led on and off, and build a first simple little board, and any of computer lying around, programming is as simple as copying, file to USB flash drive,
Great effort, and great video 👍I've got a dedicated room, but that is full of boxes too!😂😂😂 Low melt solder is great stuff 🙂Yes Digikey postage is quite expensive. I usually wait until I need a few parts for a few different items before I order to get free postage. If you search raspberry pi 4 schematic there is a partial schematic of the power supply section which might be useful. Bit of a co-incidence I recently bought an "untested" Pi setup with keyboard and case, which was posted a couple of days ago...
You are very clever to get some of things repaired on the show. I enjoy watching it. you’re very lucky to get some of it all fixed and repaired. I hope you’re making good profit out of this when you fix these things that you show on your show because I enjoy watching it all the time.
Hi Vince, are you sure all voltages are okay? Maybe there is some voltage rail Missing top bring the pi to full live?! If you search in the web for the schematics there is at least a reduced one available showing the two voltage regulators with all the rails (TP 4 - 3.3V / TP11 3.3V / TP13 1.8V / TP14 1.1V / TP15 VDD Core ?V / TP34 1V) I don't believe that the CPU is the problem here - low impedance readings in cores are actually a normal think and arent every time an Indikator for a blown chip (and in your video we can see that it is enough alive to give us a picture :)).
Love your videos thanks for doing these repairs :)!
Another great video. Shame you couldn’t get the Pi4 working. Love how you didn’t give up earlier in the video. Best wishes from the USA!
That was a great video, Vince. There are so many Raspberry Pi's that have gone wrong and very little is known about how to fix them.
The problem is more likely in the power section. It is not booting correctly because not all rails are up - or the rail you used for jury rigging can not deliver enough amps.
With defective RAM or CPU, it wouldn't boot at all.
Do not use a power bank for working with the PIs - the PIs need at least as 1.5A supply - better 3A- and most power banks only deliver 1A over USB-A. You can see the power bank cutting out multiple times - every times it does it, it could not deliver the needed current.
You tried supplying the CPU with the bench supply - but can it really deliver 5-10A at 0,8V ... because that's what the CPU needs as peak values. And the power supply, does not look like it could supply 10A.
PS: @heinrichfelder1849 provided a list of the rails with voltage and corresponding testpoints in one of the commets.
PSS: The "apparent" problems with the RAM, are likely because you used the RAM power rail to power the CPU with the hack. And it can not deliver enough power for the CPU - especially since it is too high for the CPU.
This is a great video chasing faults takes us back to the good old Vince days 🤣.
Vince, I’m confused why you didn’t look at the full schematics and mechanical drawings for the board on the Pi website? I know you like a challenge but as they provide huge quantities of documentation it is good to make use of it as it would be the sort of thing the right-to-repair campaigners are pushing other companies to provide. Just a thought. 😀👍
I was screaming this. FFS, it's open source hardware, you don't have to guess anything!
A bit like cod3r recently injecting 12V onto a 3.3V smoke release pin when a simple search would have shown what a 1117 3.3 does.
All seems to be becoming a bit electroboom but without the monobrow.
@@georgeprout42 It is not open source hardware ... to be exact: The Raspberry PI firm is about to do an IPO an be listed at the London stock exchange.
There are only limited schematics available, not full schematics.
@@TylerDurden-pk5km Don't be pedantic you know what the guy was getting at as well as I do. To not use any info on something if it's right in front of you is a bit daft.
@@andymouse It is not pedantic - the hardware information provided by the raspberry pi foundation is indeed limited.
And that's because they have NDAs with Broadcom and under der foundation is a commercial company that does not want to see it's hardware cloned - because they want to make money.
Yeah, although the schematics are incomplete (no SoC section due to Broadcom NDAs), they do list the power section with the PMIC (which was blown here) as well as the power rails. Could have saved Vince many weeks of struggling.
Epic video, Vince! Thanks for sharing the journey.
Dunno m8. If the CPU was blown or the memory cooked, it wouldnt run the bootloader (the text screen) nor the RPi OS installer shim where you can push shift and have it download files etc. That requires a fair bit of cpu/memory/peripherals interfacing. I fear the SD-card bit is gone? Tried a USB memory stick? What a tough journey. There should be schematics on raspberry pi's right? The whole idea is it is open source hardware? Thanks for another great video, i do respect the work you put in!!
There are limited schematics...but I think you may be right it all seems to be running fine, I suspect the power supply is messed up and there is no 3.3v, which is needed for the SD card. The USB memory stick is a good shout as the usb all seems to be working!
He should've totally tried USB booting
@devttyUSB0 you seem to be mixing up software and hardware. Schematics are about the hardware. And, as for the software part, the raspberry pi firmware is NOT open-source. (And it has never been)
Hi Vince, could you tell me what settings you use on your thermal camera please and whether you have a lens over it? I have a HIKMICRO model, not as good as yours, but I’d imagine they all have similar settings. Thanks
It is nice that such small computers don't have to go to waste. It would be nice to have one.
I'd like to know about that microscope station you're using there. That would come in handy for a lot of projects I could do. What brand / model is yours and how well do you like it?
@My Mate Vince What all tools do I need for electronic repair?
Not sure if it matters, but at 50:36 you can see that your jumper wire laterally pushed the component next to the RAM chip you were installing. Excellent video, as always. 🤌
Hi Vince, if I remember correctly, the Raspberry Pi needs a supply of up to 3amps at times. I bought power supplies for the sole purpose of powering them up. Your USB power brick is probably current limited to about 2 Amps. Try a variable current load on the power brick to see what the max it can deliver. If you get the Pi to boot up at all, it's pretty safe to say the CPU is working, and you probably have some RAM working, too. My guess is you are missing a power rail somewhere on the board. Get the schematics and test for all the power rails. Power rails are always the first place to look. Another tool you are not using is your scope. You compare resistance and voltages, but not waveforms on a scope. Scopes will also show you if power rails have noise or in the case of you linking two points if there are data signals on those points or just power rails.
Also, you "might" need different image files to boot the various Pi's not just the latest version, I'm not sure.
Good video, Vince. Get the schematics and go from there.
Thanks.
Thanks for taking one for the team. I also like those ZipLock™ "antistatic" bags I got to get me some of those :O) Cheers!
Great video! Random question: what microscope do you use?
15:42 I thought that you push microsd card a bit to remove it and not just pull it off?
Hello. Love the channel. Can you tell me what the name of the flux you’re using is and where I can purchase some?
the da9121 talks to the SOC (cpu) so I assume that is for power delivery ( can change the output voltage as required) for the SOC (System on Chip) so if that chip is faulty (da9121) or (SOC) could cause the the system to halt
Definately worth a revisit.
@6:17 you can see the conformal coating still on the board between bga points, at 6:24 you see that it was removed. While they are connected it could cause the chip to not sit correct. You may want to put some conformal coating between those points to make sure the chip sits down correctly.l
Have you tried the other hdmi port or wrong power adapter
Someone else may have already noticed this, but the one that registered a red light when plugged in… I think when you installed the RAM at 50:37, you can see the heatsink on the neighboring chip wiggle. I wonder if the chip underneath moved?
I also noticed the same thing. I highly doubt this was an issue. I have the 8GB model and it came with heatsinks for me to install. The glue on them wasn't very strong and I could twist them by hand without causing any damage. The hot air likely softened the adhesive, causing it to shift slightly. I would assume that heatsink is similar to mine.
Got a bit o' quality on da hand hinge m8, my very modded top drawer Seiko 4R35 with the barbed wire carved shroud on a super heavy Tuna case, I could not sleep one morning and it had sat on my desk under cover for a long long time so I thought right... load up a video and went at it in record time, fitted a set of genuine fishbone hands plus a trident second hand, thoroughly cleansed and polished inside and out, put together and finished regulating it today with 1 sec loss dial up and 9 secs loss dial down... I can live with that accuracy :D Tomorrow if screwdrivers are willing, I am going to finish off my Alba Manta Ray which is a rare rare version of the Seiko Samurai and all going well I got a 7019 Seiko Orbit to reassemble which is a lot o' class :D See, from that very first video of yours I watched I am now becoming a bit OK at doing this over the years, you helped me through 5 weeks of hell after my triple bypass and carried on becoming better at it all... cheers m8 (although daughters might say something else as I have turned my humble flat into a massive watch repair and storage facility in amongst my live steam engines, my 1958 and 1985 Lambretta and Vespa in the front room, stacked high games consoles and even higher piles of games.... thems is not happy daughters but I don't care, fixing is fun!)(btw check out Aliexpress for portable airbrush kits, I bought one for £15 came with two airbrushes, tanks, curly air hoses, little 5v air compressor and its bloody marvellous, done already couple dials and finish is superb)
A valiant effort Vince! Keep them coming!
Really enjoyed this video. Just reading some of the comments about the SD reader voltage from knowledgeable people and I'm thinking there may be a Pt. 2. :)
Also, those PMIC chips (MXL7704 in older revisions of RPi 4 and DA9090/DA9121 in newer ones) seems to be programmable via i2c bus, so you may need to set correct config register values for it to function properly.
Those registers, among others, control output voltages, mode of operation, and feedback signals. Something you definitely need to configure for it to communicate correctly with other parts of the board.
I would guess those power failure types A and B errors refer to first (DA9090) and second (DA9121) PMICs on dual-PMIC boards.
I agree with the comments. Just want to add, those 5v powerbanks are not rated for 5.1V 2.5A in reality with stable output. Rather, they allow voltage drop on the rail and the ripple and spike would be quite unpleasant in the 2A range.
Hi vince I was just watching a video of when you attempted to fix a jbl go 2 on a amazon return video and instead of buying the chip couldn't you add one of thoes charging boards you used to charge the battery and find the plus and minus on the usbc port on the speaker so it would still charge and work like normal just with a secondary charger Circuit
My fingers have never been "precision" so I adopted coating the probes with orange nail polish and use acetone on a cloth to expose only the point. Saved me from disaster many times when I slip with the probe.
Curious Marc uses some probes that are so very micro that it's amazing. It's like your idea of a probe, but it's as thin as a hat pin or sewing needle - and just as sharp. He once sent me a link and I cannot bring it to hand right now.
Great video I am glad you got the pi 3 working, Those little Pi computers are super fun to mess with. I have that same wireless keyboard touch-pad combo it is fantastic for testing computers!
You can backfeed power to them via the GPIO. It may bypass some power regulation components or burnt traces.
Bingo. You bypass the internal fusing.
I think the small chip you tried at the start isn't soldered correctly if the CPU was blown it wouldn't do anything, when you soldered it the first time it looks like you scrapped of some solder mask and i'm not sure if the BGA balls would sit correctly without fixing the solder mask
Edit: or you bought faulty chips?
I looked at that and it did look like the solder mask came off connecting 4 rows of pins.
I believe you’ve miscounted flashes. It seems like it is actually 4 long and 7 short flashes, and for RPi 4 that means Power Failure Type B (whatever that means).
8 flashes for SDRAM issues is for RPi 3 and earlier models.
Definitely 7, glad I'm not the only one who noticed!
It’s 8 on the one sent in and 7 on the eBay one. I hope Vince sees this.
@@sdjmchattie I’m kinda lost which one was which, but there’s no 4-8 blink code for RPi 4, so it seems unlikely :)
Anyway, those PMIC chips need a bit of programming to work and communicate correctly. There’s a thread on RPi forum (which I can’t link because RUclips being RUclips) discussing same problem not booting from SD card after replacing a fried PMIC chip. It is for older board revision, but I guess newer ones also require configuration.
@@p0fs no but there is 4 long to indicate it can’t read the SD contents, and there’s an 8 short flashes without long flashes before it error code for faulty RAM. So it could be two things being reported that look like they could be one long code.
@@sdjmchattie the patterns are different for RPi3 and below and RPi 4. The former uses just a certain amount of blinks (1 to 8 if I remember correctly), while the latter uses combination of long and short blinks (category and sub code). They can’t report multiple errors at once, just the one it has stuck on (like, final BIOS post code the system freezes on)
sometimes you need to use raspi charger not just and other thought this might help as i use rapsi 4b everyday
Maybe I missed the explanation, but I didn't really get the 1V trick. Why did it work? How did you know it would be worth trying? And why did you inject it at this place?
He replaced a failed rail with another one that was working with a similar voltage. But likely the other rail, can not deliver the current the CPU needs.
Hey Vince, I'm a new 3d printer and I have the ender 3 v3 ke. One tip, make sure it's stable because they have a tendency to shake when printing. May not be an issue with the pro but from my understanding it's all of them. Open it up it's fun!
Hey! I've been looking forward to this going up!!! 😜
Hi Vince, just a note to say if he put too much voltage to pin 1 of the GPIO pins i believe power comes in to the board via a different route, would also be a good place to input your bench power supply, I've had multiple PIs running various things including a model delorean so have some idea of how they work
I laughed when the probe slipped. Ive done it so many times over the years. My mate used to call me passion fingers, because he said everything I touched I f*cked! Hahaha
PI4 needs a 2amp min power supply right?
Hi, i stumbled across this video trying to find info to help repair my broken Pi. just watched the whole video and well done for keeping going. The only other similar videos I could find where by "MadeDoctor", first one of his I found a while ago was upgrading a Pi4 2GB with 8GB. He has since done a few more. I have a Pi4 that was working fine, but after connecting it to a know working Mausberry 2A Car Pi PSU and hard resetting it a couple of times, it now only has a Red LED. +5v on the 5v GPIO pin, but no 3.3v on the 3.3v pins, whih as others have suggested means a damaged PMIC.
Super effort Vince. I think there will be a revisit on this. get the 3d Printer set up, such fun. Could always do a video on setting it up
Hats off for effort loved the video. Loved the Rolls episodes also 🙂
From the look of it, that's 4 flashes and 7 quick flashes. According to some forums it's apparently an issue with a badly imaged sd card /sd card damage. It could be that the sd card made for the 2gb is not compatible and needs to be redone specifically for the 8gb model, or could try booting off a regular usb. Might be useful info, might be pointless, but just wanted to mention it.
Aren’t schematics available for Raspberry Pi?
Yes.
Just a quick thought, as the Pi4 can boot via a usb instead of the sd card. How about installing the OS on a USB and try it from that?
Don't apologize. Great video and excellent work.
I reccomend building one of the ikea lack enclosures that prusa designed. It will work gread for the ender 3 and helps control temps, not just for higher temp materials but also protects all prints from gusts of cold and what have you. If you are interested in more 3d printer shit, i actually have a prusa mk3s einsy control board, it was working great until i had to catch my printer. I caught the printer by the bed and it moved quite fast so i believe i blew a trinamic driver on the board.
Ive had a little look into this i think it might be an eeprom update rhats needed over the network, as opposed to the os needing installing
I think its missing a voltage.
Doesn't the schematic give voltages for the test points?
@1:27 - I just purchased the SKR Mini E3 v3.0 and the TFT35 touch screen to upgrade my Ender 3 (OG.) I really wanted the silent steppers. My wife was thrilled with a pair of rubber ducks. Those who know, know.
i was watching another video completely unrelated to this one(ps5 repair) but they were saying that they really had to clean the flux from under one of the chips otherwise it might not work properly perhaps deep clean the chip you replaced?
Hey, Vince. Great video. As always.
Have you tried supplying power to the Raspberry via the pin strip and thereby bypassing the USB port?
Pin 2 and 4 are 5v, pin 6 is GND. Would be an idea.
Great stuff. Well done, and thanks for a very entertaining hour. Keep up the great work
what I would suggest Vince, as you fix lots of usb stuff, is to buy yourself a switch that you put on the positive lind in, then there isn't a completed circuit until you press the power, but making sure not to touch ground with the probe until you are ready with the probe that is in circuit. then the ground probe and the switch is pressed at the same time that way there is less chance of shorting the circuit. accidents will still happen, but less common than a live circuit. just a suggestion. or maybe getting a pedal or something that you can use with your foot to activate the positive line in, or even going back to early electronics was a door mat buzzer system of creating your own switch, be an idea for another video maybe.
do not use it on high voltage items, but less than 12 volt then you should be fine to have a home made hack switch, just like a BP show.
RPis have quite a capable GPU in them, easily able to decode 1080p. However the codec has to be right, and it can be tricky to convince the browser to make use of it. You have to force RUclips to serve videos in h264 codec and check that the GPU is recognized and hardware acceleration enabled. Browsers have spotty hardware acceleration support but on higher power computers people just don't notice as the CPU decoder is fast enough.
17:30 Use a proper power supply, that might make a big difference as the newer Pis are pretty picky (and power hungry)
Any console videos coming soon Vince? I subscribed back in the day when you were trying to fix all the Xbox one consoles and I absolutely loved it! Would be great to see some more.
The problem with those is that the views suck overall
Vince are you thinking the same than me? Mounting raspeberry py 3 on your rolls royce would make it unique With parking sensors !! 🎉
Hey Vince, I'm not sure if the PI 4 is the same as the PI 3 in regards to microSD card compatibility. I know for the PI 3 there was a list of cards known to work and some that are known to not work. I think that the 128GB might be incompatible. If you try a smaller one like a 32GB it might work.
Qual é o substituto do DA9090?
Obs: Possuo um Raspberry pi 3b+ com o DA9090, ele esquenta muito e tinha curto na placa. Removi e acabou o curto, mas só acho o: mxl7704 r3 para comprar. Será que serve?
Just commenting to mention that I find the "journey" part of the repair videos more compelling than the result. Regardless of whether you're ultimately successful the video is entertaining and sometimes informative anyway.
could power starvation, set as biar-boned system, it sort of boots, plug anything in and power just not there, it all?
As for Raspberry Pi there is a power requirement which 5v 2.5 amp or higher anything less it either won't turn on or act strange as I dealt with one a few years back. Using a battery power bank won't cut it why it only output 2.1 amp
It very obviously "cut it" even multiple times and on screen ... the power of the output that is. :)
it doesn't full 2.5amps to start booting. While it's working - sure, but not to start booting and show some image on the screen.
I was so hoping you would be able to get the one that was over-volted to work. I have a RPI 1 that I shorted the 5v GPIO pin to ground by accident and now the memory chip itself gets very hot. I'm just not sure if I want to invest the money and time into fixing it. I bought the RPI-1 used on e-Bay for 20 dollars (US) and the memory chip on Alli-express is 10 dollars plus shipping? It would be cool to fix it but I just do not know if it is worth it money wise. As always really enjoyed the video.
Amazing video like always ❤️
Might be the MXL in more
mxl7704-p4 ( he do the usb side , think feeding sd card … )
and the DA9121 ( feeding the CPU , Ram )
The CPU and RAM is fine since the bootloader works fine. You would not boot at all with broken RAM or CPU.
You even download (to RAM) during network install but when it tries to write to SD card it crashes. I would check power to SD-reader part. Also make sure you have a proper power supply. The flickering green led could be a power issue. Raspberry PIs can draw quite some current. They recommend a 3A usb charger.
I would try to replace the MxL 7704 power regulator close to the USB connector.
What if short was made to SD card, did you check it? Maybe SD card went corrupted
how you charge to have look at lawn mower battery it used to charge before it storage away battery was 80%
Please Reply Can I install React OS, Ubuntu OS and other minimum requirement OS on Raspberry Pi Zero W and Raspberry Pi Zero W 2 ?
Vince there is a TVR diode SMBJ5.0A-TR which shorts when there is an over-voltage condition. You can either replace it cheaply or remove it altogether and it should work just fine.
You should check the voltage rails on the test points via the schematic. It looks like some supply failed. I don' think it's either the CPU or RAM. Probably some power-management chip has failed.
CPU is fine. The problem could be power management after the pre-boot environment. That chip you damaged is either part of that circuit or it damaged that circuit when it failed. The fact that it won't initialise without the 1 volt feed to the coils shows it needs that circuit to be present. The voltage of this circuit may step up or down depending on the state of the logic during booting, and hard wiring a static voltage to that point will only suffice to take it through the initial pre-boot stage where it needs to be 1 volt. Hope that makes sense. Also as @simonmilbourne8341 says - check your 3.3v on the GPIO if that is missing it wont be able to access the SD card to install software or read from it. This would be another indicator of a power management problem.
Vince, you need to flux on that new BGA when you hot aired'd it. You've likely created a drg joint on one or more of the balls.
I was sitting and wondering if he applied flux before heating......
You can boot a Raspberry Pi 4 or Raspberry Pi 5 with a USB stick, you can boot a RPi5 with an NVMe drive (if you've set it up).
Many of the fours would need an update first though. So make sure to do that before the SD reader gets ripped off. ;)
@@AltCutTV im not sure about that ... if i remember right, the pi 4s are from the beginning multiboot. the 3 and below needs this update, not the 4s.
@@l333ch0r Yes RPi4 can boot from USB without modification 👍
Vince your repair skills far surpass mine, but I've been a 3d printer hobbyist for years. I think you'll take to it like a duck to water once you find the space to get it set up. My "light bulb" moment was watching Thomas Sanladerer's dolly video series where he built a prusa mk2 clone from scratch using aliexpress parts.
hi i am new to your channel. have u tried booting from the USB ports to a external hard disk i heard its possible love this video i learned a lot about electronics from this video thanks :)
what bench psu is that please ?
Vince, I have an older pi 2, and i recall it can also boot from an USB stick. So if you have one without an SD card slot, you can try that!
Fantastic effort in this one.
The last bit tell a lot. It seems like the SD card has lost it's power. Installation image is small enough to fit in ram. It just failed to communicate with SD card. Check if SD Card got 3.3volt on pin no4 from the cutout angle.
Wow Vince you’re like a dog with a bone, I really enjoyed the nice long video I’m sure there’s info on these faults out there and maybe in the future comments don’t be disheartened you did what you can 😊
Pi 3 or earlier you could power with anything. From pi 4 onwards the best thing to do is use the specific power supply. I would not be surprised if they both work with the correct power supply.
Buy one Vince. You can use it with the 3d printer. I use a Pi 4 running Octopi to control my Ender 3 Pro.
Unbox the 3d printer.. I always think about buying one be good to see new users thoughts ❤
For powering Raspberry Pi without using USB-circuit, did you miss hint from Liam's letter?
5 volt to GPIO pin 2.
That's kind of dangerous as it bypasses the internal fuse.
Thank you,
Spoiler,
this was very entertaining and more like my own projects, not that I'm close to tinkering with a pie but a failure is an opportunity to learn for future success!
It may be intersting to boot off a USB drive, since the 5v rail seems intact, to see if the only problem is the sd card slot and the 3.3V rail.
You need to unbox your Ender 3 Pro! If it's the same one I'm thinking of (the S1 Pro) that is the one I will be upgrading my V2 Neo with this week when I get paid.
you can also use the raspberry pi with your ender 3d printer with a program called octoprint for remote printing, theres loads of vids on youtube about it. i have a ender 3 neo and am looking into doing this for myself hope this helps
Man I crossed the wrong pins trying to jump a brand new Mobo once. Sparks flew and the PSU tripped. PSU saved the day and everything still worked thankfully.