MacBook Pro A1286 Mid 2012 no power, no LED on the charger

[mon2]

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.

[Gigabit2]

Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger

https://www.youtube.com/watch?v=rVGMuMGH0Wc

[Gigabit2]

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 dosdude

[mon2]

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.

[Gigabit2]

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?

[mon2]

Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger

small black screen whilst loading the OS

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.

Remove the keyboard / trackpad cable and test again -> is it faster to boot ?

[Gigabit2]

Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger

All that is connected is SSD and internal display

[mon2]

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=QYLOhbrnhcA

[Gigabit2]

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?

[Gigabit2]

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.

[Gigabit2]

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.

[mon2]

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.

[Gigabit2]

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

[mon2]

Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger



Positive outtake - this is your new donor board for future repairs

[Gigabit2]

Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger

I assume there is no fix that can be done?

[mon2]

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.

[Gigabit2]

Re: MacBook Pro A1286 Mid 2012 no power, no LED on the charger

Pads are gone

[Gigabit2]

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