I was recently cleaning my pc because i noticed there was a lot of dust inside it and I had to remove the graphics card. While i was cleaning it must have knocked some of the wires or something because now that I have re-connected the graphics card all there is no picture appearing on the monitor, it is however coming out of "Power Saving Mode" so some signal must be going through. IT just remains black. I've Tried reconnecting it numerous times but the only successful attempt made the colours all wrong, everything had a deep blue tint. Also i've noticed some red lights are on the motherboard, not sure if it was like that before but thought it might be useful.
I won't jump to conclusions, but from what you tell me and my experience, that GPU is probably damaged or at least pins are dirty. Did you try to clean pins on graphic card and try it then?
If you have another graphic card, you can see if pc works, than you can be 99% sure that you damaged your graphic card in the process of cleaning.
Does your main board beeps when you turn it on, or it is silent?
It worked perfectly fine before i took out and when i put it back in the first time, but i hat to take it out again to get to the cmos battery. I have cleaned and there doesnt look to be any visible damage to it, the fan on it is turning on when i power up but i guess thats just power.
The motherboard doesn't beep when i turn it on its just silent like it normally is, only noise is the fans.