Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Can you link the video or did the link get censored? Will check it later today.
Can you link the video or did the link get censored? Will check it later today.
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
https://www.youtube.com/watch?v=rVGMuMGH0WcComment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
It is called "Repairing a Mid-2012 13" MacBook Pro with no Video on LCD" on YouTube from dosdudeComment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Ok - quickly skimmed through the video. For his case, it is the inductor @ L9000 on your board (820-3330) that was fried. He had +3v3 on pin # 1 but a ~1v2 on pin # 2 so the voltage rail on the LCD connector was too low to power the LCD panel.
We are not so lucky but you can measure again, the voltage pins 2 & 3 of the J9000 LCD connector. What voltage do you read with your meter here ? It should be a solid +3v3.Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Just booted into OS on SSD and using external display, it's a weird situation.
Slow-ish to boot and has a small black screen whilst loading the OS - but then in the OS works fine and no issues at all.
Possibly software but is the GPU failing?Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
From what I know, if your logic board is NVIDIA which the schematic shows, you should not have this fault. It is the AMD GPU that was the bad boy.small black screen whilst loading the OS
Remove the keyboard / trackpad cable and test again -> is it faster to boot ?Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
All that is connected is SSD and internal displayComment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Not condoning it so best to check with DOSDUDE1 if the NVIDIA GPUs are also flaky ?
Found this (mentions AMD only):
http://dosdude1.com/gpudisable/
PS: I am assuming that you have done the PRAM reset ?
Power off, hold the following keys, option,command,P,R (no commas) hold these keys before the start chime, and continue to hold them till you hear the start chime 2 times, then release. allow to boot, the reboot.
Watch this video - memory fault:
https://www.youtube.com/watch?v=QYLOhbrnhcALast edited by mon2; 05-03-2022, 04:15 PM.Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
The plot thickens!
So I left external monitor and LCD connected for a while after power on, about five minutes.
Internal LCD still showing nothing but external display now powered on and cursor is moving from this display to the other even though internal display not showing anything.
So seems like is not issue of recognising the display but outputting to it?Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Backlight on internal display definitely doesn't seem on, didn't see any flicker on it.
No video and shined with phone LED behind and seeing nothing.Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Hi mon2,
I was able to get pictures of the display connector under the microscope. I show them here for your views.
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
While the joints look solid, consider to flux the SMD pads -> low air pressure -> hot air these pads or high recommend to point-to-point touch each pad to reflow each contact.
The 2nd picture appears to almost show a potential short but could be my eyes.Attached FilesComment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Hi mon2,
Sadly I think we will have to admit defeat on this board as I think I damaged the connector pads too much whilst removing it.
Board is ruined
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Positive outtake - this is your new donor board for future repairs
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
I assume there is no fix that can be done?
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
There is a lot of flux in the region so cannot see the pads (if they are even there) from the posted pic.
Use Q-tip and alcohol to clean up this area and to confirm if any of the LVDS pads are still present on the board. Post a fresh pic after the IPA cleaning.Comment
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
Pads are gone
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Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger
This one becomes a donor board.
Thank you for all your help Mr Mon2, until the next time
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I am looking at an A2337 and found this for the order of power rails and what they do. Can this be confirmed before I dive into hunting down power rails that do not exist or are not neccisary?
- PPBUS_G3H (12.6V-12.8V)
- This is the main power rail that supplies power to the entire system. Check this rail first, as it must be present for other power rails to work.
- PP3V42_G3H (3.42V)
- This power rail is derived from PPBUS_G3H and is used to power the SMC (System Management Controller) and other essential circuits. It should be present if PPBUS_G3H is working correctly.
- PPVRTC_G3H (3.3V)
- This
- PPBUS_G3H (12.6V-12.8V)
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hi all!
I'm trying to troubleshoot a Microsoft Surface Pro (5th gen) model 1796 that won't power on. Motherboard model is M1007506-015. My priority is retrieving data, but the SSD is integrated so it looks like if I can't repair it it'll need to go to a data recovery company. I've done a little basic board repair before, but nothing this advanced until now. So please forgive my ignorance in advance. 😅
I found the boardview for this laptop in the forums here, and am able to open it on my PC with FlexBV.
https://www.badcaps.net/forum/troubl...-hardware-devi... -
Hi all,
TL;DR - this laptop is driving me nuts with the oddball power-related behaviors. Appreciate any insight you can provide!
I'm experiencing a power issue on an Asus Probook P5440UF-XB74. Although I've worked with electronics and computers for decades, this is my first attempt at getting into motherboard-level component troubleshooting. Any help the community can provide is greatly appreciated!
A few weeks ago I was using the laptop (on battery power) for a Zoom meeting. The battery was running very low (long meeting) but I wasn't worried about... -
I have a MacBook Pro 15" late 2011, it has a dead GPU and was sent to a repair center for this issue multiple times, the last time the original owner of this machine decided to not fix it anymore. The repair center returned the machine, but they desoldered the GPU and VRAM, it just physically isn't there anymore. The machine did originally work, we'll get to it.
What it does now: does not turn on in SMC bypass mode, the fans just twitch and I can hear a ticking sound from the board, almost like there was a short circuit. But in normal mode it does start, fans spin for about 10 seconds,...
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