PC turn on, but no display

[scarysnow10]

Hey everyone, when I was playing a game few days ago my pc just randomly lagged, made a weird trrr sound and I could see a lot of yellow glitchy squares all over the screen, then it just turned off. Since that, when I turn on my pc, everything seems to be working, even keyboard lights such as numlock etc., but I can't see anything on my monitor at all. Even when I just click the power button, it turns off without any problems.

What I've done to fix this issue yet:

reseating and clearing the ram
unplugging every hardware except cpu, psu
reseating psu atx cables
cleaning off all the dust
plugging in the speaker and hearing for beeps - when I removed all the rams, there were a lot of beeps till the computer didn't turn off, but when it's all plugged and I turn on pc, I can hear a single beep after like 30 seconds after turning on


I have no idea what to do, I'm worried that some of my hw is dead:/
If anyone could help me out, I would be really thankful!

 

[estehmami]

it seems like ur graphic card is dead is any other ports to connect ur monitor directly to ur mother board not graphic card? if there is try it
if u can try using ur graphic card on another pc to check if its working or not
it might be about 5% chance that ur hdmi or vga or whatever cable is dead try using another cable

 

[scarysnow10]

I tried connecting the monitor cable into mobo and I tried old graphic card too, still same problem. The graphic card is like 6 months old too. I'm pretty sure it is not graphic card issue right there. I've been told it may be the psu from a friend that had the same problem.