820-2523 boots but no image

[sangolossyfon]

Board spins fans at max when power connected. And draws about 35w from wall. CPU VCORE is about 1v and PP3V3_S0GPU is 3.5V. No display, USB ports have power but no usb activity. I believe this might be a VGA coil short because I read that if L8920 has less than 4 ohms to ground it indicates a VGA coil short, and L8920 on my board measures 1.5 ohms to ground on both sides. Any advice appreciated.

 

[2informaticos]

It is very likely GPU issue...

 

[sangolossyfon]

will try reflowing both GPUs and update.
curious if there is a possible way to disable one NVIDIA gpu and not the other as this 2009 has two NVIDIA gpus.

 

[sangolossyfon]

reflowed both GPUs- Now the board runs fans at max for 3-5 seconds then turns off... any way to confirm what this could be?

also, if I wait a few minutes before booting, board stays on 10-20 seconds. If I boot immediately after it dies, it only lasts 3-5 seconds before dying again.

Edit: it actually was because I hadn't attached the heatsink, so board just runs fans full speed indefinitely. same as before.

Also tested SMC bypass mode and it doesn't boot at all in this mode.

 

[2informaticos]

MCP also fails after so many years.
Refllow is not a solution for these old boards.
You can probably find working one very cheap.