PC Help Lenovo Ideacentre K320?

Around April, my PC decided it was going to stop giving a signal to my monitor. No idea why, it seems it was just out of the blue. However, it starts up fine, and as quick as the day I bought it. All fans work fine, hard drive is ticking as it always has, everything looks and sounds right internally.
Just no signal when connected to my monitor. I have tried my VGA connection in both ports, and my HDMI connection. Nothing. Checked everything inside, took out and put back in my RAM and tried two graphics cards that I know previously worked, tried disconnecting the disc driveand starting then, as well as the hard drive. Nothing.

I have tried everything I can think of. Including the classic unplug the power supply and hold the power button for 30 seconds BS. Nothing.

Anything I can do at all to fix this?

"tried two graphics cards" This shows it is probably your monitor. Try it with integrated Video.