Hi Richard another great vid explaining in clear language how to trace a short. If you did not have a low ohm meter could you have used a power supply with a current limit to trace the shorted mosfet which would in turn generate heat in the short. Obviously this would not have worked on the wire you used, but do you think it would if the fault was a real shorted mosfet.
That depends. You can't put anymore than 1V into the 'short' because if the short circuit (say it was a small capacitor) burns out and the short clears, then whatever voltage you set on your bench PSU will go into the GPU At 1V you may not get enough current in to warm anything up. Things get hot due to the wattage. If something is absolutely short zero ohms near as possible then it also will not get hot regardless how high the current is. So why will an absolute short component not get hot?? Well... Ohms law tells us that V = I/R Let's say R (the 'short') is 1 ohms a current is 5A. Then V (voltage across the 'short') = 5A/1ohm = 5V Watts = Volts x Current so with a 1 ohm 'short' and 5A from your bench PSU something would dissipate 5V x 5A = 25W and get very hot indeed! Now the lower the resistance or voltage, the lower the wattage for a given current Say you set your bench PSU to 1V and you are getting 5A into the short. The resistance of the 'short' must be R=V/I = 1V/5A = 0.2 ohms Wattage is V x I = 1V x 5A = 5W which is a lot less than 25W but still quite enough to get something hot BUT when we are considering such low resistances then the resistance of your test leads, and the resistance of the PCB tracks is a much bigger consideration so that 5W is likely to be distrubuted across all of these parts. In fact if your shorted component is actually something like 0.01 ohms and the leads and tracks are making up the other 0.19 ohms (quite possible) then things are even worse Back to ohms law Voltage across your shorted component is now V= IxR = 5A x 0.01 oms = 0.05V Wattage dissipated by your shorted component is W = V x I = 0.05V x 5A = 0.25W And the rest of the wattage (4.75W) is spread out across your leads and the PCB tracks! In this case you may burn out some PCB tracks but your shorted component will barely get warm at all There is another way to trace shorts in this sort of situation if you don't have a milliohm meter, and that is to use a multimeter with millivolt range instead - I demonstrated this, and other methods, in these video Short Circuit Tracing Techniques Part 1 ruclips.net/video/kGM-Zmrr6tc/видео.html Short Circuit Tracing Techniques Part 2 ruclips.net/video/NUgO7v4cbKs/видео.html I hope that reply wasn't too long but it takes some description and a bit of math to explain this properly.
I have never understood shorted circuits as clear as this video explained , thanks sir for your efforts and informative videos , hope you make more vids about basics as mosfets measurements
Hi Richard, thank you genuinely for your time and teachings, I appreciate it very much and looking forward to watching all of your content. Keep safe, hello from the land down under. If you ever do come over, give me a shout! Cheers
@@SureCanDoComputersServices1 LoL that's true - this is in part why I left the UK for a more peaceful backwater in the Canary Islands :) I'd be happy to join you for a beer sometime, the invitation is reciprocal :D
Hi NormSKI Great to see you enjoyed the video. I made three similar videos on this topic (but showing different techniques as well) Maybe you would like these as well if you didn't already watch them ruclips.net/video/i8TudEfD2Ao/видео.html ruclips.net/video/NUgO7v4cbKs/видео.html ruclips.net/video/kGM-Zmrr6tc/видео.html
Can't believe I'm saying this but damn I miss solving circuit problems in school, writing formulas down breaking out the calculator and working through problems, never do this anymore. I Googled about diagnosing VRM in a gpu in case I ever have my 1080 ti die. Anyway great video sir, was a joy to watch.
Great content. I am facing the problem. I replaced the Mosfet & GPU starts Working again perfectly. But after one week, MOSFET again short. Why it keeps shorting ?
@@LearnElectronicsRepair helping me learn, i been repairing GPU's and other stuff for years, your videos have helped me learn a few things i didn't know or forgot. i really appreciate you doing these
Hi great video helped a lot,found a duff mosfet on a motherboard im trying to repair, but now im stumped as do not know how to read the codes on a 8pin flat mosfet or any mosfet for the matter thanks in advance
Hello Richard, really appreciate the videos, helps us guys who are just starting from scratch and have no clue what we're doing. Do you have experience with GTX 980 Ti's?
Hi quick question should any caps be shorted on motherboard. Some smd read grounded on each side does this mean there is a short somewhere else any help be great.
Do you think it's possible to find a shorted MOSFET on an rx580 (4 in parallel) with a very high precision fluke bench meter? I'm gonna just replace all four since we've got a global parts supplier in town here I can order and pick up parts from, but I really would like to know what exactly blew
@@curtiskorb3494 I don't see how an ocilloscope would help in this case. Is the shorted MosFET from 12V or to ground? Yes A high precision low ohms meter would do the job. Bear in mind that the GPU core is a very low resistance to ground and can look like a short (especially on diode test mode)
I see that this is an old video, but looking at the drawing you only show 2 mosfets on each phase instead of 3 being 1 high and 2 low? trying to learn on graphics cards and I am so confused!!! Thanks for the video.
Hi Richard! Thanks for the informative video! Could you remove the coils to narrow down the area of the short if you don't have an ESR meter ? Obviously this means more work but would that help narrow it down?
But if I remove chokes one by one and test resistance, shouldn't a sensible multimeter find where the resistance is a bit lower, so it's closer to the shortcircuit?
Sure you can remove the chokes one by one and just use a multimeter. Removing through hole chokes is quite difficult and takes a lot of heat - that's why I looked for other methods but do it whichever way you find easiest. Personally I find this method easier than removing chokes, which to me is a last resort.
@@LearnElectronicsRepair The chokes on the AMD RX470 that I'm trying to repair are not through-hole so my soldering iron might be enough to lift one leg at the very least and break the circuit. I bought the thing as broken (as is) to try my luck in fixing it. One more question if you don't mind: I saw someone online removing a choke he suspected had a shorted phase and the GPU managed to boot in a limp mode. A short in any phase wouldn't bring the whole 12V down, regardless of trying to isolate one phase by removing the choke?
@@catalin-viorelbriceag1097 My comment about removing through hole chokes was a general one, not necessarily relevant to your GPU. But I ask a question? Why desolder chokes randomly when you can find easier and quicker ways to do it? Desoldering VRM chokes, through hole or surface mount isn't easy and most certainly is not fun, unless with something more high end like A Quick 861DW hot air and I have one and have been there, done it, and still prefer not to if I can avoid it thank you very much... so that should tell you something!! Yes you could remove the choke on the shorted phase and possibly the Mosfets depending what has failed, and it is possible the VRM will run and the GPU power up and run (the likely-hood of this working comes down to the type of VRM controller and what it is monitoring) One shorted phase WILL bring down the whole VRM unless you repair or, if you are lucky, isolate it.
@@LearnElectronicsRepair I will try finding the short. It's my first time doing this but I have faith. I'll look for more videos, yours included, and I'll somehow get to the bottom of it. The knowledge I get from this far outclasses the work or a broken GPU that was broken to begin with. Thank you for your advice and patience in writing.
@@LearnElectronicsRepair Hello again! I got updates. I got around to test the card a bit more while powered up. It's an RX470 Expedition from ASUS. It has 3.3V, 12V, 1.8V, VPEX, 5V and VMEM. It doesn't have VDDCI and VGPU. No MOSFET is blown up, no short that trips OCP. I probed around a bit and found that somehow the MOSFETs are getting 12V on the high side ones, no 12V on the low side ones (hope I'm not mistaking which is which). Is that a possible issue with the MOSFET drivers? All phases seem to do the same thing. What are their purpose actually? Are they telling the MOSFETs to turn on and off? Your response would help me a lot. I got this card as is for educational purposes and in hoping to repair it to either sell it and get a hot air station and some other goodies to help me get started to try and repair more GPUs or just put it in my mining rig and see how it holds up.
Very often there is one high side mosfet and there are two low side mosfets in parallel giving a total of three. The two low side mosfets are switched on and off simultaneously (the gates go to the same output on the PWM controller) and quite literally share the current between them.
Im having issues with my rgb light on my gpu. Sometimes the lights are on, Sometimes half the light come on and sometimes none come on. Need a little help with this. I dont want to send it in
A graphics card that runs Android emulator games only and DX 11, 12 and 9 games do not work until I installed it on another motherboard, the same problem and I updated the bios and nothing changed. I want to know what is the problem with the graphics card Evga 1060 6g SSC
Hi Richard, I have a power board for a game device that provides zero voltage on one of the connector pins (the pin was supposed to output 34 volts. others pins showed the correct voltages eg. 5v, 8v. I've also checked the voltage supplied from the dc jack connection port and it is correct). I tracked one of the components on the board and traced it to a capacitor and the + sign joint showed it was shorted to the ground. Thus, I removed the capacitor and the problem still showed up when I did a continuity test on the joint where the capacitor was unsoldered. The capacitor is not the issue. What's your advice for me to find the root cause?
Hi Muhammed - as I realy don't know anything about your PSU, I suggest you register at www.badcaps.net/forum which is free to join. Then post the fault description and some good quality pics in the PSU repair section and I am sure you will get some advice www.badcaps.net/forum/forumdisplay.php?f=32
Hi sir, I just need your help if you like .. I am not professional but it’s my hobby to repair stuff I have XFX rx 580 8GB card and it’s not giving display.. when I turn on pc then fans start spinning in few seconds it’s resting but no display.. it’s GPU getting heated when fan started I check with meter. I have 12v 3.3v 1.8v 1.5v but no display 😣
hey im looking for a discord server to join i have a 980 ti my sister was using until it stopped working the other day i got it and it powers on but only with 1 12v power cable in and needs 2 too run i plu the 2nd in and it cuts out the pc and i have to reset the psu i have a feeling this might be the issue but still ild like to chill and learn more what do you think ?
I'm setting up a Discord server (well actually it is already there but I am doing some more work on it before launching it). It will be ready soon and I will let you all know when it is ready
@@LearnElectronicsRepair thats awesome im hoping to setup a lilttle repair's bench i first tock a vcr player when i was 4 with my uncle im 33 now i got a lot to learn thinking of college now my partners family own a massive sigh making complen so will be good when hardwere brakes also it will be great to make freinds with you and the others
@@ItzRuleBlitz Welcome to the party :D The best way to learn this is to do it. You need some basic equipment (multimeter, soldering iron (get a T12 and you will never regret it) a hot air station and a bench power supply) and that is enough to start repairing. Then go and buy, or scrounge from friends, some faulty things and try to fix them :D For setting up your little repair bench you might find these two videos interesting soldering & desoldering equipment ruclips.net/video/x8qBmTrX2v8/видео.html test equipment ruclips.net/video/lutL4wft6fQ/видео.html Have fun, enjoy what you are doing, even the failures, and you will learn 100% guaranteed
This a bad idea - also you didn't mention if the shorted Mosfet is a high side or low side? If you did remove one phase (both high side and low side, then the remaining three phases will be running at 133% of the intended load. Also the VRM controller may not even run at all with one phase disabled. Actually you should be thinking of replacing *all* the Mosfets in the VRM, not just the shorted one. Also you need to check the gate drive resistor connecting to the shorted one from the VRM controller IC, And consider changing the controller IC as well. Oh and don't forget to check for a shorted or low resistance load that may have caused the Mosfet to go short in the first place. To be honest, I just checked and you can get 10x MDU1513 for less than €5 www.aliexpress.com/item/1005003785263714.html So I can't see why you would even *want* to run the card without it?
@@LearnElectronicsRepair Thank you so much for helping. I'm still not able to determine if it's low or high side (I'm an amateur) I have 15 total Mosfets five have the MDU1513 model and ten have MDU1511. Can I E-mail you a photo? The reason why I thought of doing so, is because the card sometimes run normally even under full load, and sometimes it doesn't. And I forgot to mention that I had shorts on three of the MDU1513 Mosfets and after cleaning the card with a contact cleaner the shorts were gone, so I tried to run the card, it ran normally for about 5 mins then at idle it gave a random full screen mono-colour (as usual) so I took it off and checked the same Mosfets and out of the three only got one shorted, I ran it again at full load now I have the same three shorted again. And I rarely get 6 beeps from the Motherboard while trying to run it by the way.
@@PorscheMan. If you have five of the MDU1513 and ten of the others, then the MDU1513 are the high side mosfets. In a VRAM there are either an even number of high side and low side (in your case 5 of each) or there are twice as many low side than high side. never the other way round What you are saying does not make a lot of sense - if you have a shorted high side Mosfet, then the ATX PSU would not even power up due to the short I think you are getting a little confused somewhere with your resistance readings
@@LearnElectronicsRepair Now I understand what low and high side mean, thanks for being so patient with me. I'm sorry if I didn't sound clear. What I do is, put the multimeter on continuity mode and have the common/black probe to the card's ground like you do, then check the Mosfet's Gate and I get a continuous beep. Another way is that I put the multimeter on 20k ohm and check the same Gate and I get no resistance unlike the working Mosfets which all have roughly 12k ohm.
Hi Richard another great vid explaining in clear language how to trace a short. If you did not have a low ohm meter could you have used a power supply with a current limit to trace the shorted mosfet which would in turn generate heat in the short. Obviously this would not have worked on the wire you used, but do you think it would if the fault was a real shorted mosfet.
That depends. You can't put anymore than 1V into the 'short' because if the short circuit (say it was a small capacitor) burns out and the short clears, then whatever voltage you set on your bench PSU will go into the GPU
At 1V you may not get enough current in to warm anything up. Things get hot due to the wattage. If something is absolutely short zero ohms near as possible then it also will not get hot regardless how high the current is.
So why will an absolute short component not get hot??
Well... Ohms law tells us that V = I/R
Let's say R (the 'short') is 1 ohms a current is 5A. Then V (voltage across the 'short') = 5A/1ohm = 5V
Watts = Volts x Current so with a 1 ohm 'short' and 5A from your bench PSU something would dissipate 5V x 5A = 25W and get very hot indeed!
Now the lower the resistance or voltage, the lower the wattage for a given current
Say you set your bench PSU to 1V and you are getting 5A into the short. The resistance of the 'short' must be R=V/I = 1V/5A = 0.2 ohms
Wattage is V x I = 1V x 5A = 5W which is a lot less than 25W but still quite enough to get something hot BUT when we are considering such low resistances then the resistance of your test leads, and the resistance of the PCB tracks is a much bigger consideration so that 5W is likely to be distrubuted across all of these parts. In fact if your shorted component is actually something like 0.01 ohms and the leads and tracks are making up the other 0.19 ohms (quite possible) then things are even worse
Back to ohms law
Voltage across your shorted component is now
V= IxR = 5A x 0.01 oms = 0.05V
Wattage dissipated by your shorted component is
W = V x I = 0.05V x 5A = 0.25W
And the rest of the wattage (4.75W) is spread out across your leads and the PCB tracks!
In this case you may burn out some PCB tracks but your shorted component will barely get warm at all
There is another way to trace shorts in this sort of situation if you don't have a milliohm meter, and that is to use a multimeter with millivolt range instead - I demonstrated this, and other methods, in these video
Short Circuit Tracing Techniques Part 1
ruclips.net/video/kGM-Zmrr6tc/видео.html
Short Circuit Tracing Techniques Part 2
ruclips.net/video/NUgO7v4cbKs/видео.html
I hope that reply wasn't too long but it takes some description and a bit of math to explain this properly.
Thank you Richard a very concise answer thank you for taking the time to reply, I never even thought about using the millivolt range 🙄.
@@trone32 Did you see this video I made?
ruclips.net/video/P_2GGNr4q1s/видео.html
This is so underrated. Sharing this to everyone in the gpu community I know of.
Thank You
Another great lesson. You're the perfect "further education program" for the unexperienced recent tech level graduated student.
I have never understood shorted circuits as clear as this video explained , thanks sir for your efforts and informative videos , hope you make more vids about basics as mosfets measurements
Thanks. Yes I am making a beginners video soon, about \mosfet and how to test
Hi Richard, thank you genuinely for your time and teachings, I appreciate it very much and looking forward to watching all of your content. Keep safe, hello from the land down under. If you ever do come over, give me a shout! Cheers
That I may do when I learn to live upside down :D :D :D
@@SureCanDoComputersServices1 LoL that's true - this is in part why I left the UK for a more peaceful backwater in the Canary Islands :) I'd be happy to join you for a beer sometime, the invitation is reciprocal :D
Very clear. I've seen a lot of vids where they are just guessing until the short goes away, at least this can hone-in on the specific one.
I'm glad you enjoyed it - I do my best to make my videos really clear, but then they sometimes get quite long LOL as I don't skip over stuff.
Very clear instructions as always, I personally find longer videos better, because you can learn more from them!
Great video, appreciate the way you explain and introduce other tools to assist diagnostics.
Hi NormSKI
Great to see you enjoyed the video.
I made three similar videos on this topic (but showing different techniques as well)
Maybe you would like these as well if you didn't already watch them
ruclips.net/video/i8TudEfD2Ao/видео.html
ruclips.net/video/NUgO7v4cbKs/видео.html
ruclips.net/video/kGM-Zmrr6tc/видео.html
Can't believe I'm saying this but damn I miss solving circuit problems in school, writing formulas down breaking out the calculator and working through problems, never do this anymore. I Googled about diagnosing VRM in a gpu in case I ever have my 1080 ti die. Anyway great video sir, was a joy to watch.
YES! I wanted to fix a GPU & this video is perfect! I don't have to remove mosfets one by one now!
Glad it helped!
I love the uncut videos
It's what I do :D
god bless you , i learn a lot from you , really appreciate you !!
Amazing...keep doing.great work sir...we always stay with you.
@@LearnElectronicsRepair most welcome
Fantastic my new favourite ee guru
Wholy shit, this channel is a god send for me
amazing video man!
Like your practical repair explaination! Keep up the good work!
Thanks! 👍
Nice video, keep up the good work :)!
Glad you liked it :-)
Great content. I am facing the problem. I replaced the Mosfet & GPU starts Working again perfectly. But after one week, MOSFET again short. Why it keeps shorting ?
Awesome video
great content man, ty
My pleasure!
@@LearnElectronicsRepair helping me learn, i been repairing GPU's and other stuff for years, your videos have helped me learn a few things i didn't know or forgot. i really appreciate you doing these
Hi great video helped a lot,found a duff mosfet on a motherboard im trying to repair, but now im stumped as do not know how to read the codes on a 8pin flat mosfet or any mosfet for the matter thanks in advance
Great explanation. Thank you!
You're welcome
thx for sharing
Hello Richard, really appreciate the videos, helps us guys who are just starting from scratch and have no clue what we're doing. Do you have experience with GTX 980 Ti's?
Yes I have looked at some of them - really the same technique applies to all of them the same. pretty much
Hi quick question should any caps be shorted on motherboard. Some smd read grounded on each side does this mean there is a short somewhere else any help be great.
Do you think it's possible to find a shorted MOSFET on an rx580 (4 in parallel) with a very high precision fluke bench meter? I'm gonna just replace all four since we've got a global parts supplier in town here I can order and pick up parts from, but I really would like to know what exactly blew
I've got an old hp Oscope I don't know how to use, would that help?
@@curtiskorb3494 I don't see how an ocilloscope would help in this case. Is the shorted MosFET from 12V or to ground? Yes A high precision low ohms meter would do the job. Bear in mind that the GPU core is a very low resistance to ground and can look like a short (especially on diode test mode)
I see that this is an old video, but looking at the drawing you only show 2 mosfets on each phase instead of 3 being 1 high and 2 low? trying to learn on graphics cards and I am so confused!!! Thanks for the video.
Hi Richard! Thanks for the informative video! Could you remove the coils to narrow down the area of the short if you don't have an ESR meter ? Obviously this means more work but would that help narrow it down?
Yes you can! Just the other way is less work as you mention.
Got a msi r9 390x 8gb gpu. Powers on fan spin msi logo lights up but no post or video to the screen. I'd like to have it fixed. You interested.
But if I remove chokes one by one and test resistance, shouldn't a sensible multimeter find where the resistance is a bit lower, so it's closer to the shortcircuit?
Sure you can remove the chokes one by one and just use a multimeter. Removing through hole chokes is quite difficult and takes a lot of heat - that's why I looked for other methods but do it whichever way you find easiest. Personally I find this method easier than removing chokes, which to me is a last resort.
@@LearnElectronicsRepair The chokes on the AMD RX470 that I'm trying to repair are not through-hole so my soldering iron might be enough to lift one leg at the very least and break the circuit.
I bought the thing as broken (as is) to try my luck in fixing it.
One more question if you don't mind: I saw someone online removing a choke he suspected had a shorted phase and the GPU managed to boot in a limp mode. A short in any phase wouldn't bring the whole 12V down, regardless of trying to isolate one phase by removing the choke?
@@catalin-viorelbriceag1097 My comment about removing through hole chokes was a general one, not necessarily relevant to your GPU. But I ask a question? Why desolder chokes randomly when you can find easier and quicker ways to do it?
Desoldering VRM chokes, through hole or surface mount isn't easy and most certainly is not fun, unless with something more high end like A Quick 861DW hot air and I have one and have been there, done it, and still prefer not to if I can avoid it thank you very much... so that should tell you something!!
Yes you could remove the choke on the shorted phase and possibly the Mosfets depending what has failed, and it is possible the VRM will run and the GPU power up and run (the likely-hood of this working comes down to the type of VRM controller and what it is monitoring)
One shorted phase WILL bring down the whole VRM unless you repair or, if you are lucky, isolate it.
@@LearnElectronicsRepair I will try finding the short. It's my first time doing this but I have faith. I'll look for more videos, yours included, and I'll somehow get to the bottom of it. The knowledge I get from this far outclasses the work or a broken GPU that was broken to begin with.
Thank you for your advice and patience in writing.
@@LearnElectronicsRepair Hello again! I got updates. I got around to test the card a bit more while powered up.
It's an RX470 Expedition from ASUS. It has 3.3V, 12V, 1.8V, VPEX, 5V and VMEM. It doesn't have VDDCI and VGPU. No MOSFET is blown up, no short that trips OCP. I probed around a bit and found that somehow the MOSFETs are getting 12V on the high side ones, no 12V on the low side ones (hope I'm not mistaking which is which). Is that a possible issue with the MOSFET drivers? All phases seem to do the same thing. What are their purpose actually? Are they telling the MOSFETs to turn on and off?
Your response would help me a lot. I got this card as is for educational purposes and in hoping to repair it to either sell it and get a hot air station and some other goodies to help me get started to try and repair more GPUs or just put it in my mining rig and see how it holds up.
Hi :) On your VRM schematics you have 2 mosfets per phase but on GPU you have 3 mosfets 1 high and 2 low. Why?
Very often there is one high side mosfet and there are two low side mosfets in parallel giving a total of three. The two low side mosfets are switched on and off simultaneously (the gates go to the same output on the PWM controller) and quite literally share the current between them.
@@LearnElectronicsRepair Thanks :)
Im having issues with my rgb light on my gpu. Sometimes the lights are on, Sometimes half the light come on and sometimes none come on. Need a little help with this. I dont want to send it in
A graphics card that runs Android emulator games only and DX 11, 12 and 9 games do not work until I installed it on another motherboard, the same problem and I updated the bios and nothing changed. I want to know what is the problem with the graphics card
Evga 1060 6g SSC
On my gpu it boots into windows and no beep code but no display what could it be though
Hi Richard, I have a power board for a game device that provides zero voltage on one of the connector pins (the pin was supposed to output 34 volts. others pins showed the correct voltages eg. 5v, 8v. I've also checked the voltage supplied from the dc jack connection port and it is correct). I tracked one of the components on the board and traced it to a capacitor and the + sign joint showed it was shorted to the ground. Thus, I removed the capacitor and the problem still showed up when I did a continuity test on the joint where the capacitor was unsoldered. The capacitor is not the issue. What's your advice for me to find the root cause?
Hi Muhammed - as I realy don't know anything about your PSU, I suggest you register at www.badcaps.net/forum which is free to join.
Then post the fault description and some good quality pics in the PSU repair section and I am sure you will get some advice
www.badcaps.net/forum/forumdisplay.php?f=32
@@LearnElectronicsRepair Hi again Richard, Thanks for recommending me to the forum. I've never been there so will have a look.
Спасибо👍
Hi sir, I just need your help if you like .. I am not professional but it’s my hobby to repair stuff I have XFX rx 580 8GB card and it’s not giving display.. when I turn on pc then fans start spinning in few seconds it’s resting but no display.. it’s GPU getting heated when fan started I check with meter. I have 12v 3.3v 1.8v 1.5v but no display 😣
hey im looking for a discord server to join i have a 980 ti my sister was using until it stopped working the other day i got it and it powers on but only with 1 12v power cable in and needs 2 too run i plu the 2nd in and it cuts out the pc and i have to reset the psu i have a feeling this might be the issue but still ild like to chill and learn more what do you think ?
I'm setting up a Discord server (well actually it is already there but I am doing some more work on it before launching it). It will be ready soon and I will let you all know when it is ready
@@LearnElectronicsRepair thats awesome im hoping to setup a lilttle repair's bench i first tock a vcr player when i was 4 with my uncle im 33 now i got a lot to learn thinking of college now my partners family own a massive sigh making complen so will be good when hardwere brakes also it will be great to make freinds with you and the others
@@ItzRuleBlitz Welcome to the party :D
The best way to learn this is to do it. You need some basic equipment (multimeter, soldering iron (get a T12 and you will never regret it) a hot air station and a bench power supply) and that is enough to start repairing. Then go and buy, or scrounge from friends, some faulty things and try to fix them :D
For setting up your little repair bench you might find these two videos interesting
soldering & desoldering equipment
ruclips.net/video/x8qBmTrX2v8/видео.html
test equipment
ruclips.net/video/lutL4wft6fQ/видео.html
Have fun, enjoy what you are doing, even the failures, and you will learn 100% guaranteed
Holy Hannah……………Wolfman!!
so can you do these tests with a multimeter in resistance mode i wonder ?
No you'd need a milliohm Meter, at least! 😉
THIS!!!
"A short video" xD
You wouldn’t happen to know the wattage of resistors they use on the 30 series vbios chips would ya lol
I don't. Usually you can work out the wattage by the physical size of an SMD resistor, 0402, 0604, 1208 etc
@@LearnElectronicsRepair yeah they are just so damn small thanks
@@supupandaway8138 IMHO just replace with the same size as the original and the wattage will not be a problem
Is it safe to remove one shorted MOSFET (MDU1513) and run the card without it? It is one out of 4 on the same rail/lane
This a bad idea - also you didn't mention if the shorted Mosfet is a high side or low side? If you did remove one phase (both high side and low side, then the remaining three phases will be running at 133% of the intended load. Also the VRM controller may not even run at all with one phase disabled.
Actually you should be thinking of replacing *all* the Mosfets in the VRM, not just the shorted one.
Also you need to check the gate drive resistor connecting to the shorted one from the VRM controller IC, And consider changing the controller IC as well. Oh and don't forget to check for a shorted or low resistance load that may have caused the Mosfet to go short in the first place.
To be honest, I just checked and you can get 10x MDU1513 for less than €5
www.aliexpress.com/item/1005003785263714.html
So I can't see why you would even *want* to run the card without it?
@@LearnElectronicsRepair Thank you so much for helping. I'm still not able to determine if it's low or high side (I'm an amateur) I have 15 total Mosfets five have the MDU1513 model and ten have MDU1511. Can I E-mail you a photo?
The reason why I thought of doing so, is because the card sometimes run normally even under full load, and sometimes it doesn't. And I forgot to mention that I had shorts on three of the MDU1513 Mosfets and after cleaning the card with a contact cleaner the shorts were gone, so I tried to run the card, it ran normally for about 5 mins then at idle it gave a random full screen mono-colour (as usual) so I took it off and checked the same Mosfets and out of the three only got one shorted, I ran it again at full load now I have the same three shorted again. And I rarely get 6 beeps from the Motherboard while trying to run it by the way.
@@PorscheMan. If you have five of the MDU1513 and ten of the others, then the MDU1513 are the high side mosfets.
In a VRAM there are either an even number of high side and low side (in your case 5 of each) or there are twice as many low side than high side. never the other way round
What you are saying does not make a lot of sense - if you have a shorted high side Mosfet, then the ATX PSU would not even power up due to the short
I think you are getting a little confused somewhere with your resistance readings
@@LearnElectronicsRepair Now I understand what low and high side mean, thanks for being so patient with me.
I'm sorry if I didn't sound clear. What I do is, put the multimeter on continuity mode and have the common/black probe to the card's ground like you do, then check the Mosfet's Gate and I get a continuous beep. Another way is that I put the multimeter on 20k ohm and check the same Gate and I get no resistance unlike the working Mosfets which all have roughly 12k ohm.