Hello
This isn't really a linux/hardware question, more of just a hardware question. I didn't know where else to turn.

I recently bought an Xtacy Geforce 4 128 meg ddr video card to replace my ancient Gefore 2 64 meg card

All seemed fine...
Until I turned the machine on.

I have a KDS Visual Sensation 19 inch monitor, and it kept showing the "No Signal" error.
I made sure everything was plugged in etc, no difference.

I put my geforce 2 back in, booted up and it worked fine.
I figured I had a bad card so I took it back and got a new one.
I got home, screwed it in, but I got basically the same thing.

This time it showed stuff (along with the "No Signal" error)
like my MSI limited edition bright red screen and the bios screen
but it was all jumbled up, could not read it etc.
I checked the cables in the back of my monitor, all was well.

I decided to try another monitor, just in case.
I got out an old AOC 17 inch monitor, hooked it up to the geforce 4, booted, and it worked flawlessly.

I wondered if my KDS monitor went bad, so I hooked it up to my friends machine who has a geforce 2 and it worked fine.

I don't know what to do to fix this. I checked every site about my hardware and found nothing.
Any help would be appriciated.
Thanks.

Sounds familiar. I have a GF4 MX and a Samsung 959 NF. I had similar problems with my box and the reason was seemed to be my powersupply. I had a 230 W ps and every now and then I had some kind of problems. Switching the PS of a couple of times usually fixed the problem. Then I bought a 300 W PS and the problems were gone. I also had strange problems with my XFree86. Sometimes I couldn't boot to X and the error message was: "no screens found". Every single mode was out of h-sync limits! All this even though I hadn't changed anything since last session. In this case I had to switch of my monitor and unplug the powercord. Even this problem was gone with the new PS. I hope this might help you.