I was building a new computer recently, and as I didn't have a monitor for it yet I borrowed an old one from another computer. It worked fine, so when I got my new monitor I put it back on the computer it originally came from, but now it seems to be getting no signal. Checked to make sure it's plugged in properly, tried rebooting PC, nothing. The monitor works fine on all my other computers, it just seems to be that one it has an issue with. Any ideas?