Hi fellows, I’m new here, driven to this board in my quest for help for my problem. So far no one seems to have an answer to it and it’s driving me crazy. Sincereyly hope you can help me out. First the specs. Here they are: System specs: mobo: Asus P5B (basic edition) CPU: Intel C2D E6400 2.13GHz, 2 MB cache CPU cooling: Zalman CNPS9700 PSU: Antec Earthwatts 430W memory: 4 GB of DDR2 PC5300 (2 Kingston, 2 Dane-Elec sticks, Dual Channel) storage: 2x Maxtor sAta HDD 250 GB (one of which is boot disk) 1x Samsun sATA HDD 500 GB graphics: Asus 8800GT 512MB, new batch with one slot cooler (originally MSI 7900GTO) drives: Lite-On sAta DVD burner, don’t know exact model generic card reader case: Coolermaster Centurion 534 with back and side 12mm fan. Side casefan and CPU fan are controlled by a Zalman fanmate. External devices: - Logitech MX 3200 wireless desktop set, USB - BenQ FP937s 19” monitor, DVI - Oki B4100 mono laser printer, USB - Canon CanoScan LiDE 70 scanner, USB - WD Elements 400GB external HDD, USB - Logitech Z4 2.1 speakers - Netgear WGR614 wifi router OS: Windows XP Pro SP2, fully updated. AVG antivirus, Zonealarm firewall, Microsoft Defender, Spybot Search & Destroy, all properly updated. Haven’t had any infection problems AFAIK. Three user accounts on the pc, but mine is the only administrator account. The Problem: During normal operation I suddenly lose all video. Subsequently the pc won’t boot properly, that is it seems to boot fine but I get no video. I see the mobo splash screen for a moment but then the screen goes black, with no cursor. I can’t get into the bios either. From the looks and sound of it all components start up fine but I get no picture. History: First encountered this early december 2007, after the system had been working flawlessly for over a year. To try and solve it I went through the usual steps: disconnecting all nonessentials, reseating graphics card and memory, trying separate memory sticks in separate slots. Nothing worked. Eventually I did a CMOS reset by removing the battery, and after that it booted fine and everything went back to normal, for 24 hours. Then the same thing happened again. So I sent the system back to the supplier (without my hdd’s and Windows install, they didn’t need it). When they plugged it in it gave a “overclocking failed” message and then booted fine, only tho crash after a few hours. So they switched the motherboard and PSU and sent it back. It worked fine for a day, then the same problem occurred. Sent it back to the supplier, it worked fine over there. Basically they couldn’t reproduce the problem but decided to switch the graphics card (MSI 7900GTO -> Asus 8800GT). I got it back and it worked again, just that the 8800GT crashed in several games when running at clock speeds. Before I had a chance to figure that one out, the system crashed again, same deal, no video. Sent it back a third time, apparently the graphics card was faulty and they switched it for a new 8800GT from the new batch. I had asked them to test the system extensively because the problem seemed to appear only after a day or so. They couldn’t find any more problems but when I got it back it crashed again within a few hours. So I went through all the moves again, also changing the sATA cables, ending with another CMOS reset. This time it didn’t do the trick and now I got stuck with random memory error beeps at boot attempts. I then decided to take it to a local pc store to see if they could find the problem. By now I was convinced it had to have something to do with my HDD or install because that was the only thing the supplier hadn’t tested, so I left that in. At the store they plugged the pc in and it worked fine. They had it running for three days without any problems. They ran all kind of stress tests and benchmarks and tested all the hardware, couldn’t find anything wrong. They suggested it might be related to an external device and adviced me to start with a minimum setup. So I went home and hooked up nothing but a keyboard, mouse and monitor. No boot. So what was different in the store then at home? I tried another DVI cable, other monitor, other keyboard, other power cable, other power group in the house. No boot. So I brought it back to the store, and yes it worked fine over there. They too were out of explanations, basically because they couldn’t reproduce the problem. When I took it back home again and plugged it in, tadaa! It booted fine. However, it seemed to boot a lot quicker then it used to do and it gave an error on bootup “detecting drives done, no any drives found” right before Windows started. On this forum I found out this was caused by the JMicron raid controller on the mobo which was notorious for causing mysterious problems. So I disabled that in the BIOS and it looked like my problems were finally solved. The system worked for two days with numerous reboots and it seemed stable. Until suddenly during a game I lost video again. A simple cold reboot fixed it at first but a few hours later the same thing happened again and now it seems I’m back where I started. When I try to boot I hear the one beep from the mobo, all the fans start up and after a short delay I can hear all the drives spin up and all the peripherals wake up, but I have no cursor. On startup all I see is the mobo splashscreen and sometimes the post messages flash across the screen for half a second or so before the screen goes black. The only thing I haven’t tested yet is the DVI connection on my monitor. I hooked it up to another pc and it worked fine but that pc only had a VGA output, and I can’t test that on my pc because the 8800GT only has two DVI plugs and the P5B has no onboard video. Maybe I should mention: for the two days that my system worked before it made the last crash it wasn't quite stable. These are a few things I remarked: I suddenly lost connection with the external hdd while transfering large files. Had to unplug and replug it before Windows recognized it again. After one reboot it totally failed to see the network controller, another reboot nad it was fine again. While playing MOH Airborne there was a weird glitch: everything appeared fine only in the ingame movies all characters were silhouettes and it didn't show the sit map in the briefing sequence. Sorry for the very extensive post but I tried to be as complete as I could. I’m not a real tech wizard, so I’m not sure what is relevant or not. I hope you guys can help me because I’m at my wit’s end. I’m close to throwing it out of the window.