Unusual PC problem... just blacks out

Legend · 4 Nov 2011 at 22:56

Funny problem this, and 90% of the time it will occur within 5 minutes of starting up the system. It doesn't happen all the time, maybe 1 out 10 ten times. My monitor will just go dead, and nothing will respond. I know Windows isn't running behind, as nothing responds and I can no longer hear audio, so it can't be the monitor at fault.

I've also had a much rarer issue of starting up and seeing the screen go all basic colours and 'psychadelic', and again just freeze. Plus, now and again, I will get small pixel blocks of the screen that look like this in Photoshop (but not elsewhere for some reason). It's strange.

This leads me to believe it might be the graphics card? I'm not sure though. How can I troubleshoot this and find out what's causing the problem? It's very frustrating. :confused:

*I have a GTX 470 (not oc'd).

DazQ87 · 5 Nov 2011 at 00:38

Problems like these always seem to be power supply (not enough juice) or overheating/borked graphics card. What is the full spec of your PC, in particular the power supply?

Legend · 5 Nov 2011 at 00:48

Hadn't thought of that. The PSU is the oldest thing in my system, although by no means ancient, probably about 4 years old. It's a Corsair HX620W. I also have an i5 760 2.80GHz (with a Corsair Hydro H50-1 Cooler), Gigabyte P55 mbd, 4GB RAM and a Gigabyte GTX 470. I also have a Zalman VF3000-F cooler fitted to this, so not sure if that could be an issue. Temps are fine across the board though, and as I say, this problem will occur nearly always within 5 minutes or so of starting the system, sometimes almost immediately. In fact today it happened 3 times in a row within 10 seconds of the system booting in to Windows. It hardly ever happens when the system has been running for ages, although I've had the odd blue screen, but that's rare.

Another funny thing that I noticed recently, although it may not be connected at all... I bought the CPU, mbd and RAM bundle, (from OCUK) with the CPU being overclocked to 4ghz, and I know it was as I remember seeing it in a speed test I ran when I got it. But for some reason, it is now running at 2.8 stock speed. I've not changed anything, nor have I updated the bios. :confused:

The_Bullet · 5 Nov 2011 at 16:46

See this thread here http://www.evga.com/forums/tm.aspx?m=586183 , as a possible "fix" (didn't work for me), and other threads on that forum describing your issue. I had the exact same thing with my old Zotac gtx 470, a couple of times a month (on average) on boot, or after exiting games I would get the black screen (and very occasionally the "psychadelic" colours). It appears to happen when the clocks/voltages are entering their lowest state. I never had problems in game. The card was tried in two completely different systems with the same result, so it was obviously the card. However, trying to RMA with such an issue as this, with it only happening occasionally, is a nightmare.

Legend · 5 Nov 2011 at 17:37

I always thought it might be the GFX card given the nature of the problem. Kind of makes sense. Mmmm, tricky one then. Looks like I'll just have to deal with it. Annoying.