2011 mbp 820-2915 - Pink screen w/Boot sound

Joesipaq

New member
Hey all,
Got brought a dead MBP, client states he brought it in for maintenance a few years ago to another shop. After a year, he says it didn't power on randomly, so he pulled the bottom case and said that he found a screw floating around in the system on the mobo. Says he kept it for another year, decided to try and charge it randomly - when it gave the boot sound but no video.

(Before repairs preformed so far, there was no screen image or backlight) System fans and disk power up once for about 6 seconds, then off for about 5 then on again until I power it down. No screen or boot chime for the first cycle.

To the jucie details. Q9560 was welded to the mobo. Click image for larger version  Name:	S20171205_0001.jpg Views:	1 Size:	309.7 KB ID:	28896 Repealed Click image for larger version  Name:	S20171205_0002.jpg Views:	1 Size:	305.0 KB ID:	28898 that's working fine now.

Wasn't getting any voltage on pin 4 (gate), figured that whatever got in, went out to U9500. Replaced and now im getting a strong 1.52V on my PP1V5_GPU_REG.
I'm getting a pink or purple screen, after pram reset a white screen once. "image" looks torn or what I would imagine from a dead gpu.

Reistance from P1 on L9560 (gpu_reg) is 0.9 ohm or in diode mode 0.001 dead short. U8500 and U8550 get burning flesh hot after seconds of on time.... Do I have some bad ram or a shot GPU? or both...

Opinions (with some explinations?)

Im going to guess, that what ever took out Q9560 was pretty hard and did something to the PP1V5 that would take out the U8500 and U8550 and potentially the GPU, but I havn't had experience with this before.

Next move to pull U8500 and U8550 to see if the short disappears?

Thanks and happy repairs!
 

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smiba

New member
Like ielectron said, if its not the GPU now it will be tomorrow.

but Q9560 is the high driver mosfet for PP1V5_GPU_REG so it probably killed the GPU anyways
 

Joesipaq

New member
Alright, thanks guys! - For future reference for a quick sheet - What models should I be weary of? MBP 2011-2013 15" or all sizes?
 
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