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

[ielectron]

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.

 

[dukefawks]

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

 

[ielectron]

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]

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.