HP EliteBook 840 turns on then off no display. (Chip level motherboard Repair.)
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- Опубликовано: 23 ноя 2024
- Laptop powers on then off with no display is a very common issue, especially in HP laptops, I have been receiving many 840s G1, that's why I made this video to demonstrate to you how to fix it.
This issue happens mostly due to missing 1.05V chipset voltage, in worst cases it happens due to a short circuit chipset where it becomes quite hard to fix, this issue is not caused by Bios as others say.
In this video I use a digital multimeter to diagnose a faulty chipset power supply chip (TPS 51362) by comparing voltage readings from the schematics, then I proceed to diagnose a fault power sequence chip (op amp lmv393v) that is not giving out power good signals (PWR_GOOD_3). Then I replaced both fault ICs using a soldering rework station (Brower).
If you a having this issue, follow the video you will successfully be able to fix it.
How to download laptop schematics. • How to download laptop...
Download a pdf document that explains the meaning of different Schematics codes and abbreviations from the link below. drive.google.c...
If you enjoy this video, give it a thumbs up, if you have any questions put them in the comments below or write me by email, and don't forget to share and subscribe so that you can be notified when I upload more videos in the future
Love the way this teacher explains with patience and has a backstory on the hp. Great fix
Thank you
I am impressed seing an African this good, you motivate me to work and study hard as a fellow brother in the same field. Thumbs up bro👍
Haha thank you
Mine is hp8440p keeps blinking blue n orange when I connect the charger what might be the problem
New subscriber from the UK. Your videos are very knowledgeable, thanks for sharing.
Thank you
I have hp probook 4320s with the same problem but i don't think anyone here can do the repair as you did.
Grt job new subscriber from Pakistan working in same field bro❤
Hi. Ap kaha kam karty ho. Mery laptop me ye masla hai
Buy some small nuzzles for your hot air gun. That way you focus your hot air on the area you want, avoiding thermal shocking other components or plastic parts and you can put/pull components faster.
I do have them but its better with no nuzzle the heat is distributed evenly that makes chips come off easily without smoking the motherboard
Great job.👏 Would love to learn how to read and understand motherboard schematics
Thank you, You can checkout this course that goes into detail of schematics reading and repair. www.udemy.com/course/laptop-repairs-using-schematics-diagrams/?referralCode=66A7C5DDED0CAC9BD21E
@@platinumphonesandcomputers This is awesome. Thanks alot
great step by step schematic review and that has challenged me as a technician based in nairobi moi avenue as i have encountered this problem severally with 840 g1 and g2 but have never solved it...you are a one great mind i'd like to work with...can i get your location or where you are based?..
Thank you brother, I do work from Kampala Uganda
@@platinumphonesandcomputers are you conducting a class for repair? I also interested with your lessons ..... Pls may I get your contact too
@@maduhueddy5076 yes we are, where a you from?
Hey boni, uko nairobi side gani, can you help me with this exact problem
Hae bonface , am in nairobi my laptop has same problem, am in anairobi can you help?
i am experiencing exact same problem right now, but the fan is not rotating, just same light coming up on and off.
i have no idea who can tackle this for me.
Bro same problem
How to fix this?
If fan is not spinning might be a RAM or Power Good Chip
you can check out this other video on the same laptop but a different issue. ruclips.net/video/ok4tDRE9cVQ/видео.htmlsi=JU3skyPznTTEXgDy
Good job, very nice explanation. Thank you
You are welcome!
@platinumphonesandcomputers Hi, I'm curious... Do u have any idea why SPI chip may get erased except aborted bios update process? I am fixing Dell Optiplex which has the same symptom and I noticed that SPI chip is erased, istead a bios firmware, it had reppeating itself string of bytes... What do you think, is that possible that it could get erased by shorted 3V3alw and 1.05V supply rail, because I had also shorted LDO for 3v3alw and mosfet in 1.05 supply rail...
Awesome work dude
I have 840 G1 but the back light is faulty sometimes it comes on then after a minute or two it goes off. Where can I tackle specifically
Thank you, the backlight you should start with the fuse near the screen connector, even a screen can also be a suspect
@@platinumphonesandcomputers we are dealing in the same industry, I replaced the screen, changed all the basics. In fact when I connect the laptop to the external display the inbuilt screen comes on but when I disconnect the external display the laptop stays with the light but after a minute or two then it starts to blink and it goes dark again
Please what is the function of the jumper and the reason for disconnecting it at 2:50
. Thanks
its just a power rail that connects the secondary pwr supply to its load, if you break it,it helps you to determine the direction where the short comes from...is it from the load's side or the pwr supply side??
@@hillaryaura7244 thanks for the response I really appreciate
many thanks to you , i got the solution from you
Thank you sir for the teaching. Can I be your student
Yes you can, I have courses on Udemy
hp 9470 folio turns on and stop and start again. how will i go about it
Hey hallo, nyc tutorials over here,,,now now now ,tell me what happens when u decide to fool the Ec or KBC by injecting the 3.3v LDO on that final pwr good rail signal?will the ec allow the processor to switch on and the pc will it work?
No unfortunately it wont, there other internal circuits inside the chip that also need to function with the true power good signal.
Could you share for me schematic HP 840 G1 UMA, thank you so much ❤
Can you please link me to where I can get the schematic elitebook 840 g3
Where are you located? I need mine repaired asap in nakuru
Amazing Brother! :)
I have a question, does this method works with HP 820 G1 ? I am not able to
find its schematics anywhere
Yes it should, 840 G1, 840 G2, 820 g1 All there schematics resemble that of 840 G1, if you are a keen enough you could fix all of them with 840 G1 schematics
Excellent explanation.
Glad you liked it
I changed my eeprom just like u guided!
It worked!
Thanks!
But it turns off itself automatically every 30mins and I turn it on again without any problem!
Do u any idea what that might be? And what I should do?!
Thanks
Clean ME Region will solve your second problem
Check the thermal circuit and make sure the fun works
Hello chaz, i am having same fault in my Hp Compaq Pressario Cq61, if l press power button it turns off within. 1 second just a blink of light on the lcd, screen, I downloaded the schematic s but could not figure it out which IC chip i have to look for can you please help me out,. Thanks
Most times that is due to thermal issues, missing feedback signals or secondary circuit short. Check the boot sequence of that motherboard in the schematics and verify if all the SO signals are present
My hp elitebook 840 g3 doesn't turn on
I power it on and the battery light blinks 8 times then the capslock blinks 1 long one then the laptop turns off. What could be the issue?
Most likely batt. Try,
- Remove the batt., connect directly to ac power.
- if that does not work, remove one RAM and try power it on, or switch the RAM sticks
Please help me with hp 840 g1 not turning on, keep blinking one time whenever you put adapter charger
check charger middle pin
Thanks
tanks , but what is the electronic name of the u7400?
Its an operational Amplifier, the chip name is LMV393DMR2G
I enjoyed this video. I have some challenges, please, can you be of help?
My HP note book i3, does not start only that the lead charger light keep on blinking when I insert the charger cable and plug it on. What could be the problem.
checkout this video. ruclips.net/video/Qbxs7OfGXBk/видео.html
NICE EXPLANATION THANK YOU
Hi i have a hp probook 6470p that has the same problem, how can i get intouch with you to fix it
You can follow the video and fix it otherwise you can maybe get a Technician nearby
Hey, my hp elitebook 840 g4 has black screen issue and it started when I accidentally kicked the charger while it was charging. I need your location or contact details
Check about page
kindly do more videos on 840 g1 and g2
Sure i will
Nice work sir.
Thanks
How do you fix the issue with this computer dying when it reaches 19%?
That is probably a battery issue
@@platinumphonesandcomputers I've switched my battery twice within the lifepan of me having this PC. I also forgot to point out that mine doesn't come with Bluetooth
Mind blowing!
by tha way friend..how did you come to arrive at chip u7400 ??!!...am a little bit confused there.
Yaa that's the chip that gives out all system power good signal, it was short. The video was quite long, I cut off that part
Raw talent🎉
Thanks
Mery pas laptop hai usme ye problem hai k laptop ko charger connect karta hon to laptop off ho jata hai phir on ho jata hai asay hi on off on off hota hai charger bhi change kar k dekha hai please reply
Check out this video. ruclips.net/video/ok4tDRE9cVQ/видео.htmlsi=1bSjSNOcaOaeSP76
good video, thanks for the knowlegde...
Thank you
please help with hp 9470, the charge LED blink white and orange but it does not display
Check charger, charging port and charger ID circuit
Can I get the schematic diagram
I have the same laptop and it Turns on with display and then turns off. Is it the same problem with urs, please help me.!!! 🙏
If you see the display its not the same issue
@@platinumphonesandcomputers finally I figured out that the problem is with the power port. there is a disconnection of wires.
Same Problem hp elitebook 840 g1 power on but no display, Mechanic says it won't be good (Bangladesh)
Send him the link of this vdeo
I have got the same problem on HP ELITEBOOK 840 G4 till now not yet sucessful
Same here... is it fixed now ??
Have you tried to diagnose the motherboard what are you findings? Let me know then I can see how to advice you
Is there an alternative to this chip? lmv393v
Yaa that's an operational amplifier, any other OP Amp will work fine
best explanation
Thanks you
Good job
Very good
How much does this cost to have fixed?
Usually depends on your location
can you send me schema in hp 840 g3 please
❤️❤️❤️❤️❤️
Thanks allot
Grateful thanks alot
You're most welcome
Nice
Can I get the shcamatic 840 g2
Yaa you can search on google its there
Bro my laptop is having same problem plz help
If you follow the video, you can fix it
Im having same issue with 2 g4s
You can follow the video and fix them
Nice one man, learn something new
mine dam same problem
i need bios full flash hp 840 g1
send me an email
Hello
Hey
Wah😂