820-3332 power cycle MacBook Pro (Retina, 15-inch, Early 2013)

ielectron

Member
i dont see any liquid damage on the board, very clean, customer did not mention damage too, only that before it would come up without black screen, only typical solution i found the u8900 resolder, i removed it, replaced the solder to new, and put back the original chip as i dont have in stock now, but same thing, the G3H 12.5V is very stable, and i can see 3.3V and 5V coming up for a moment, the fans are spinning but every 1 sec the slow down a bit, no video, no chime, no light in usb mouse, PPVCORE_S0_CPU goes to 1.1V , but cycles too, like everything else but G3H.
I was looking for missing component, the customer opened it up and removed the SSD before, but he said the issues started before he opened it up, but under the scope i did not see knocked off components.

As i did not see any liquid damage i did not put in the ultrasonic yet, but maybe its worth a try?

I will order the 62882C chip anyway but that takes few weeks, that could be bad? or the resolder should fix that?

forgot to mention , its powering on only when i connect the charger too, and when i remove the charger it wont work on the battery only, dies right away, could it be the battery, i dont have that in stock too.
 
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dukefawks

Administrator
If you screwed something up with U8900 it will cause this issue. Did the machine power on before you messed with it?
 

ielectron

Member
it was powering on, but it was the same issue, i mean started up without chime, display or backlight, but now i remember that the fan was spinning real fast after 1 minute, so yeah it was not power cycling before i resoldered the u8900, i ordered a donor board from aliexpress and the the chip u8900, customer accepted already it will take weeks.

Now if i killed u8900, than replacing it should revert what i caused, but than what caused the original issue of no chime-display issue?

At the moment the CPU gets hot so its not dead, but even before there was no light on usb mouse.
 

dukefawks

Administrator
It could be so many things. There is no need to take off U8900, just heat it up and drag the soldering iron over the pins. I have no idea how much heat you put on the board and messed with the CPU/GPU on the other side.
 
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