Two days ago I started having some odd issues with my system. I was playing the Witcher when my screen went black and the sound started skipping. I couldn't get back to the Windows desktop to check what was going on - it was like my monitor had been turned off. The system was still on, I just had no signal. I restarted and it happened again.
I checked all my temps (fine), ran some stress tests with monitors running, but it didn't happen again.
Today it started up again. The first time I had the case open when it did it, and I noticed two things. First off, as soon as it happened, the video card fan spun up to maximum speed. It didn't slowly increase as it normally would when temps go up, it just went from slow to max in a second (and temps were still fine.) The second thing that happened was that I have a small, low power case fan attached to the extension from one of the 6-pin adaptors on the video card. When the system crashed, that fan stopped.
I was thinking video card problems (which wouldn't make sense in retrospect, as the leads to the fan go from the power cord directly to the fan, not through the card), but when I hit the reset button, it started to reboot then turned right back off. I booted again, and it started to load Windows, then went right back off, like the whole system was losing power. This happened several times.
I'm guessing motherboard or power supply, but I don't have any way to really test, as I don't have access to another system, nor do I have any spare parts available.
I don't have the money to guess wrong (my car just went into the shop today with a bad cylinder, and I'm a single dad with a pitiful income), so I really need to narrow the problem down before I can think about looking for solutions. Any advice would be welcome.
The core components (including PS) are three years old, the video card is one.
~GIGABYTE GA-EP45-UD3P LGA 775 Intel P45 ATX Intel Motherboard
~CORSAIR Enthusiast Series CMPSU-650TX 650W ATX12V / EPS12V SLI Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply
~Intel Core 2 Duo E8500 Wolfdale 3.16GHz LGA 775 65W Dual-Core Processor
~ G.SKILL PI Black 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL4D-4GBPI-B
~MSI N460GTX CYCLONE 1GD5/OC GeForce GTX 460 (Fermi) 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card
~HT | OMEGA STRIKER 7.1 Channels PCI Interface Sound Card
~Western Digital Caviar Black WD1001FALS 1TB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive (main drive)
~Windows 7 Home Premium, up to date
Are you over clocking?
What settings was Witcher on at the time?
Does the PSU smell funny?
Is there any blown caps on the MOBO?
Have you completed optional windows updates? (most people dont)
Have you completed a windows diagnostic yet in the pre-boot setup?
There is one other thing I'm testing this morning that I hadn't thought of before. The whole system was plugged into a power conditioner/UPS. It's a top line model that was given to me, and it has been there so long that I hadn't really thought about it. It was just a part of the outlet in my mind. I don't have a lot of experience with UPSs, but I wonder if a failing one might cause a sort of brown out condition. I swapped it with a generic power strip this morning, so we'll see.
That would be an easy fix, but I'd hate losing the power conditioner. The wiring in this house is old. When I say old, I mean that this house has much of its original wiring, and was one of the first houses in town the get them newfangled electric lights.
I hate when I google a tech issue, find someone's post about the exact issue, and find they never posted the solution.
So, a final update: I've been running my system for a full week now without a single hiccup or issue. The only thing I changed was to get rid of the UPS and use a plain old power strip. The UPS was a $900 model that had been given to me after the business it had been in closed, and has been in constant use since probably 2002.
So, for the record, it looks like the odd power symptoms I was experiencing were caused by brown-outs, and it looks like a failing UPS can cause just that, failing to put out the full power it is supposed to.