I'm really puzzled here, I built my own desktop a few years back and I'm good at fixing computers, both software and hardware, but I cannot figure this one out.
Computer is frequently shutting down randomly on its own. Sometimes it will stay on for two days and sometimes only for a half an hour.
About a month or two ago I tried to turn on my computer and double-tapped the power button on accident. Not sure if the double-tap has anything to do with it, but my computer tried turning on and then something popped and it shut down; PSU fried. Sent it in for an RMA and I got a new one. Plugged it all back in and it booted up fine, but after a little while the random shutdowns started. Here is a list of actions I've taken to try and resolve the issue:
- Pulled out each stick of Ram (3 total) and tried running the system with only one at a time. Every stick got tested by itself.
- Pulled out each video card (I have two) and ran it with one and then the other. Computer still shut down with either of them.
- Pulled out all HDDs except for my main OS HDD.
- Unplugged peripherals
- Checked to make sure PSU is on right voltage setting (it is)
- Made sure all fans are running; case fans, cpu fan, video card fans, PSU fan (its a coolermaster case with 4 huge fans so its not a circulation issue)
- Formatted OS HDD and reinstalled Windows 7
- In Windows 7, put power settings on Balanced (this seems to keep the computer from shutting down, but I haven't done extensive testing)
- Took apart the entire desktop and cleaned every part: Reseated CPU fan to CPU with new Thermal Sealant (Arctic Silver 5)
- Took apart one of the video cards and reseated its processor with the Sealant
- Installed both GPU monitoring software and CPU monitoring software: Both GPUs average around 55-60 Celsius and the CPU around 45.
- Placed the GPU fans and CPU Fan on max speeds (they get a lot louder and the temp drops to the 40s for the GPUs.
- Stress tested both CPU and the GPUs and it didn't trip the shutdown, even when the temperature for the CPU was hitting 71 Celsius and the GPUs were also in the low 70s.
- Changed BIOS settings to stability mode for the CPU (instead of TURBO), also set the BIOS so it warns me if the CPU temp hits 80 Celsius
- RAM (3 Sticks): G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBPQ
- MOBO: GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard
- Case: COOLER MASTER HAF 932 RC-932-KKN1-GP Black Steel ATX Full Tower Computer Case
- CPU: Intel Core 2 Quad Q6600 Kentsfield 2.4GHz LGA 775 Quad-Core Processor
- GPU 1: EVGA 512-P3-N871-AR GeForce 9800 GTX+ 512MB 256-bit DDR3 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
- GPU 2: Its the 8800 version of the above one
- PSU: ETASIS ET750 True 750W, Max 850W ATX12V / EPS12V SLI Certified CrossFire Ready Active PFC Power Supply
- HDDs: 4 of them
- OS: Windows 7 Ultimate 64 Bit
I've exhausted all my knowledge besides going out and buying new parts and testing the new parts in the system to find what's causing the problem. Any ideas?