Something in my system is killing my video cards. My motherboard died after I replaced my PSU with PC Power & Cooling Silencer Mk II. The symptom was the power was on 1 second and then off. I changed the psu back to OCZ ModXStream Pro 700w with the same result. I tried the same motherboard with a no name 300w PSU with a very low power requirement video card with the same result. I assume the motherboard is dead.
I got a new ivy bridge motherboard and with my amd 7950 with PC Power & Cooling Silencer Mk II. No video output from 7950, but with output from onboard video. Windows 7 didn't detect presence of 7950. I changed the 7950 with a 6970 and everything worked fine.
I took the system from the bedroom with AC back to my study room. The power went on for 1 second and then off as soon as I tried to turn on the computer.
I couldn't get the computer back on in my study. At the time, this happened, both rooms were not on AC and room temperatures were similar. I took the whole computer back to my bedroom and retest the system. The computer would turn on in the bedroom. There was no video output from both 6970 and intel HD4000. I took 6970 out. HD 4000 has video output again. As soon as I put 6970 back, there are no video from neither 6970 nor HD 4000. Now I don't know what had killed my 7950 and 6970. The same PSU was used in whole episode. As right now, I have a working system in the bedroom. Monitor used in the bedroom is a viewsonic 24" 1920x1200 via HDMI or DVI and in my study, I have a dell 19" at 1280x1024 via DVI and dell u2711 at 2560x1440 via miniDP.
In the bedroom, the psu is plugged to a regular power bar and in the study, the psu is plugged to a APC UPS.
I am afraid to move my computer back to my study. Any helps?
Take the APC UPS with it? It might be some weird power fluctuations in the wall messing things up. The UPS should tell you if the walls power is good or not.
Other than that I'm kinda stumped. Oh and when you plugged in the 7950 and got no video what I would have suggested doing was going into the bios and checking to make sure onboard video is disabled.
One other thought, when transfering the system from one spot in the house to the other, you might need to redisable onboard video. (the cmos battery might be going dead so it might not save the setting... even though its supposed to check if there is a video card in the slot whilst powering up...)
^ then again that wouldn't have explained why your video card wouldn't work in the bedroom after not working in the study even after you tried onboard and not.
Edit: long shot but you are using the proper cables right? not somehow putting a cpu 4/8pin connector onto the cards, and its an actual 6/8pin PCIE cable.
Power cables for video cards and motherboard were properly plugged. I had bios set to auto and PCI-x for 7950. I haven't tried bios change with 6970 because I just moved the computer from one spot to another. The computer is aware of the 6970 because of both integrated and discret video were not working. The circuit of UPS broke when I tried to start the computer the second times after the initial on and off for 1 second. I thought it could be bad power from the wall. The UPS should have caught it. If it were the PSU, should it would kill both motherboard and video card. It doesn't make sense why the system works fine when it was in the bedroom.