My old graphic card SAPPHIRE HD 6870 wich is broken and run only in VGA mode needed 500W 2x 4PIN new GPU needs 450W 1x4PIN. I have 650W power suplly. I indeed pluged all in. Maybe I should try flash BIOS that I never did before in any PC.
Because it started with you watering it. It is very likely the cause of problem some steam might be still in it and making wrong connection. Not much you can do about this , maybe put it in rice for two days , open casing if possible.
I have new graphic card and when I turn on PC I have black screen (no signal) and it is not problem between monitor and GPU because OS is not booting. Not even keyboard startup blink. My old GPU works and sadly I dont have motherboard with intergrated GPU.
I tried removing jumper for clearing...
When you dont have drivers on GPU it doesnt mean that you cant use GPU for displaying anything on monitor. Intergrated GPU do nothing unless you set it to do something. When I deleted GPU driver for my broken card , then it worked like in safety mode in win7.