Hello all. I have what it seems to be a rather complicated issue, as I've looked for help in like 3 other forums, but the problem remains. The problem is "simple". I turn on the computer, and after a few seconds, or mintues, the computer shuts down completly, incluiding the PSU. The time always changes. It sometimes shuts down after 2 seconds of turning it on, and sometimes it gets to the windows installing screen. The thing that keeps me worried the most, is the fact that I don't even know clearly wich is the source of the problem, although what I've investigated about this problem tells me that most likely, it's the PSU. Hope you guys can help me out a bit. The computer components are: SAPPHIRE RADEON HD3870X2 PCIE16X DX10 1GB EP35C-DS3R LGA775 C2DUO 1333 DDR2/DDR3 PCIe CASE THERMALTAKE VH8000BWS ARMOR+ MX MIDTOWER WO/PSU PSU HEC ZEPHYR 750W PFC FAN 120MM SLI 20+4 PINES HARD DRIVE HITACHI 500GB SATAII MEMORIES DDR2 CORSAIR TWIN-X 4GB (2X2048) 6400C4 800MHZ PC2-6400 CPU INTEL CORE 2 QUAD Q6600 - 2.4 GHZ 1066 MHZ QUAD 8MB LGA775 B COOLER TT CL-P0310 BIG TYPHOON 120 VX COBRE HEAT PIPE AMD/IN I also have a screenshot (taken with cellphone) of the computer BIOS' PC Health screen. (One thing about that. The memory voltajes read 2.1V, because I tried to rise the voltaje as I red in other forums, that could have solved the problem. I loaded the BIOS optimal settings now, in wich the memories have 1.8V default voltaje). Here it is: Here's a screen shot of the POST screen: I really hope anyone can tell me how to fix this! Thanks in advance! Oh, and finally. I'm sorry if this doesn't belongs here.