PC won't boot, no beeps, fans are running, black screen

Hello, the other day I turned on my PC and it didn't boot, the fans and everything are working, the monitor is plugged in correctly, just stays black, no beeps when I turn it on.

There's a green light on the motherboard, i've tried switching graphics cards, I've been searching my house for a VGA adaptor to plug my monitor into my motherboard, but no luck , I still haven't found one so I can't test that right now.

I tried taking out the motherboard battery for a couple minutes, pressing the power button for 1 minute, moving the ram from slot to slot, no luck.

Do you guys have any idea what I could do to fix this problem?

Have you tryed changing the motherboard battery ?

I didn't change it but I did try to remove it for a couple of minutes, put it back, but I dont have any other batteries,

Should I go and buy a VGA adaptor, with a battery and try those? (to test if it's the graphics card or not)

try remotely connecting to the machine just to confirm if it is a videoo problem.

if you remotely connect fine then its a vid issue if not then you maybe looking at something else.