Video not working.

So today I took apart my pc to clean out the cpu and psu and such.

After I have put it together I am not getting any video. At first I thought I might of fried my video card, but the on-board video isn't working either.

The wierd thing is that I am still getting a signal, because when I plug my monitor in either my video card or on-board video it switches from "No signal" to just a black screen and orange led light. Any suggestions?

Wiggle the VGA cable a bunch. Try a different monitor, if you have one.

I have tried both those things.

But I have realized something even wierder. I initially thought I was getting troubles with my pc because the cpu was overheating pretty bad, but now I think it might be my PSU. Half my hardware works and the other half doesn't. My mouse has power, but my keyboard doesn't. Also the fan on my PSU isn't running...but my cpu fan and pc in general works. Still no video. Any ideas?

Get a new PSU. Period.

Is it alright to have a psu with my more watts than is needed by your pc?

that is the best thing to do. if you get one that barely meets the needs it'll just burn out fast like your old one did