820-3330....yeah I just want YOUR opinion on what to do

[JohnB8812]

I got this in today. Board turns on and chimes has no image on the screen. I opened the bottom lid and saw THIS. How should I proceed? (You can be explicit too because this kinda pissed me off when I opened it lol)

 

[JohnB8812]

I do have 3.3 volts on GPUVCORE_EN

 

[dukefawks]

Clean it up and replace corroded resistors and traces. Not much else I can say before that is done.

 

[JohnB8812]

Ok will do

 

[JohnB8812]

Ok so back to this mess. Replaced corroded resistors/burned caps near that area and reflowed U8900. Now I have a green light and 1.5 volts on PPBUS_G3H... The only thing on the entire board getting any heat when I connect the charger is the GPU. It's not insanely hot, but it is getting warm.

 

[JohnB8812]

And the light is kinda intermittent not really stable. 3.42 volts on 3v42 tho

 

[JohnB8812]

PPDCIN: 18
CHGR ACIN: 4.36
Resistance between 17 and 18 2.9 ohms
27 and 28 22.3 ohms

PPBUS is 1.5 so would this be an ISL issue now?

 

[JohnB8812]

3.3 on ACOK

 

[dukefawks]

Q8930 is now shorted sending 12V to the GPU. U8900 is dead for sure and Q8930 too. Could have been caused by corroded traces and whatever you did to the area around U8900. Pray that the GPU survived......

 

[JohnB8812]

Fuuuuuck ok. Are there more transistors I should replace along with it to avoid anything else from happening?

 

[dukefawks]

Why not replace all the FETs and U8900. Also need to figure out why it shorted. Corroded traces and resistors can cause this, so double check everything.

 

[JohnB8812]

Ok was thinking that on the fets. I’m gonna go with possibly the gigantic chunks of ground plane burnt off the board causing the issue but not sure so will check

 

[JohnB8812]

Ok so pulled fets and U8900. Underneath where Q8930 was the transistor fell apart, but the board does not look bad at all like no explosion or burned layers or anything. Also pulling them relieved a short on PPVIN_S5_HS_GPU_ISNS Ordered chips and mosfets, so fingers crossed the GPU is not dead lol

 

[JohnB8812]

Replaced fets and ISL and got power back but no video internally or externally GPU got 12 volts the end

 

[dukefawks]

GPU power ok now? Not that hard to replace GPU/VRAM on these.

 

[JohnB8812]

I don't have the resources for replacing the GPU unfortunately if I did then I would def try it if you think it's not too bad. GPU power appeared to be ok definitely not shorted to ground fan spins, chimes, but absolutely no video even with a known good screen or plugged in externally.