After adding some RAM and a card reader, I BOOTED my computer and got a "no signal" message on the monitor (connected via DVI). I tried attaching it via VGA, but same result. I then opened the case & moved the video card to another PCIe slot, and it worked. I disconnected all the cables to reassemble the case, rebooted, and again got the "no signal" message. Assuming that my video card was bad, I bought a new one, but still get the "no signal" message. I've tried the new card in both PCIe slots as well. I've tried removing the new RAM and card reader, but that doesn't make a difference. Any ideas?

If any of this helps: I just built the computer a few months ago. RAM is dual channel. First video card was XFX GeForce 6200 TurboCache / 64MB GDDR2. New one is XFX GeForce 7300 GT / 512MB DDR2. I'm running XP Pro.Try cleaning the PCI slots for the card...being careful of ESD (Electrostatic Discharge). Make sure the card i properly seated and the cables are properly attached.what MOTHERBOARD do you have and cpu ? Did you build this or buy it ? Mobo is an ABIT KN9; PROCESSOR is a Athlon 64 dual core 3800. I built this computer, but am no expert (can barely assemble one). Not knowing ANYTHING about hardware, I have a suspicion that the mobo is the problem. It ran fine until I added the RAM & card reader. Is there something on the Mobo that controls both PCIe slots that could have gone on the fritz? Can't really TEST them w/ another card (non-video), as there's no display.

Re: the first suggestion: I'm quite confident that the PCI slots & boards are clean, as all are new. Just built this in June.