I am having some odd issues with my brothers computer. There were issues with the screen not getting any input, but the computer would be starting up fine, no beeps or anything. I attempted using different screens and cables and still was no signal. The computer did used to work fine, just one day after waking from sleep mode stopped sending a signal.
I tried replacing the CMOS battery and this did not fix the issue. Using the Intel HD graphics through the motherboard work (VGA plugged into MB instead of Graphics card). However plugging into the graphics card it does not work. The odd thing is that if you fiddle around swapping the ports and turning it on and off eventually after many attempts there will be input again when plugged in via the Graphics card. And it all works fine... until a reboot or waking from sleep mode, in which case there is no signal again.
I have also tried totally replacing the graphics card with a brand new one, still the exact same issue as before.
I am unclear at this point what I can still test to figure out the problem. I have tested cables, screens, cmos battery, resetting cmos, reflashing cmos/bios, and even replacing the graphics card.
What else could be tested here?