I have been running my computer for about 7 months with the 7770 and the 6670 inside of it and it has worked perfectly. I recently purchased the 5830 card, but when I installed it with the other two cards and the monitor connected to my 7770 the computer started up until the windows logo and then turned off. I tried taking out the extra two cards and starting it with just the 5830, but when I did the computer wouldn't even go to BIOS. When I press the power button, the fans all spin but the computer doesn't beep, the monitor doesn't turn on, and the vga light on the motherboard is red. I have both 6 pin connectors plugged into the card. The computer still works if I take out the 5830 and put back in the other two cards. Any ideas on why it's not working and how I can get it to work?
(I know these cards cannot be used together with crossfire...you'd be amazed by how many people give me that as an answer even though it solves nothing. I use my extra cards for mining as well as my main card whenever I'm away from my computer.)
I don't know if the card is defective or not, I don't have another computer to test it on. I don't think it's a power issue because 850W is more than enough for this card and the same psu has been fueling both the 7770 and the 6670 with no problem.
I purchased it used. The person I bought it from said that they tested it before shipping and it worked perfectly. It appeared to be well packaged, but it may have been damaged. I can get a replacement, I just don't want to go through the hassle and possibly run into the same issue if there's something wrong besides the card.