So, I built a computer for my younger brother a few days ago. It wasn't a perfect build, but I got all the problems worked out in due time, except for one. This happens rather frequently, actually. The monitor will suddenly go black and pop up a message saying that it is entering sleep mode. I can't be sure if the computer is in fact hanging at this point, but I'm fairly confident that it is.
The problem seems to happen at random, but most of the time fairly quickly. Starting up a game will cause the problem to occur in seconds, most of the time. But this also happened when I was first installing Windows on the machine. Sometimes, the computer won't even post, no beeps sound. This last bit happens rarely, though, and turning the computer off for a short while generally fixes that issue.
Looking at these symptoms, I suspected overheating to be an issue. I ran speedfan to look at temperatures, though, and they all looked well under control. The CPU was only running at 40 Celsius, and that was the hottest temp at the time. To my chagrin, however, as I noted the 40 degree temperature of the CPU, the video blacked out again.
I checked to make sure the video card was securely seated in its slot, which it was. I suspected insufficient power from the PSU, but I'm disinclined to believe that. Everything in this computer was actually my old computer, minus the new hard drive (which is the same size and model of the one I used before). Since I didn't have any problems with it before, I more or less discarded that idea. To be sure, though, I tried powering up the system with the CD drive, two fans (they had the big 4 pin connectors), and disconnecting the extra power inputs to the video card. Unfortunately, no luck there. I would think that even if the PSU was the problem, disconnecting all that stuff would have been a large enough reduction in power consumption to stop it, yes?
One more thing before I finish real quick. Twice I managed to get the computer running for an extended period of time. My brother was able to play a game for the duration of a match and shut it down without any problems. Starting it back up again, it still worked fine. But the problem did eventually return. Unfortunately, I can't really figure out what I DID those two times. The only thing in common with both occurrences was that I entered the BIOS, maybe made a small change or two. But, I didn't really make any changes in there relating to the video card or anything. Maybe a problem with the BIOS itself, and I should flash it?
Any thoughts? And thank you for the help, in advance!
Edit: Forgot to mention system specs!
Athlon 64 3500+ CPU
1.5GB DDR RAM
ATI x1950GT AGP video card
MSI K8N Neo-2 motherboard
WD 250GB SATA2 HDD (running at SATA1 speeds)
500W PSU (21A on 12V rail)
Hmmm...lots of potential problems here. To eliminate the major/obvious stuff as possibilities:
A: Make sure NOTHING is overclocked.
B: Try using some different ram.
C: Re-seat your video card
D: If you're power supply is having trouble, reducing the load isn't always going to work. Try it again in your old system (if it's practical to do so) and see if you have any problems. Perhaps something was damaged during the removal/installation.
E: It's also possible that there is a problem with your motherboard, but since this can be more difficult to troubleshoot, try the easier things first.
Nothing in the computer is overclocked. I've never really felt comfortable with doing so. I'm far too cheap to spend money on nicer cooling systems than is necessary =P heh.
As for RAM, I don't have any other sticks to try out, unfortunately. However, Memtest86 didn't turn up any errors.
As for trying to use the power supply in my old system... well, this computer IS my old system. Just a new case and hard drive. However, I do now believe that the power supply is at fault here. I took my newer power supply and put it in this system earlier today and have yet to have any problems with it. I'm going to watch it another day or so to be sure. I was at work all evening and didn't get to personally test it at all. But so far, it seems as though a new power supply would be the solution. Hopefully thats all there is, thats a pretty easy fix after all.
As for the manufacturer of the psu, its just a generic brand, I'm sure. Xcase, the sticker calls it. I picked it up way back from a friend of mine whose family owns a computer parts & repair shop. Its done pretty well for the past three years or more... maybe its just too old, and it was time for it to go, eh?
Also, one other piece of evidence pointing to the PSU, perhaps. I should've mentioned this at first, but forgot all about it. When I pulled the power supply out of the box I had stored it in, I noticed the little plastic ring around the wires coming out had broken. Apparently, the ring extended into the PSU itself, as there was plastic rolling around inside the power supply. In hindsight, trying to use it at the point was probably really stupid of me. Might have melted or something and gotten gunk all over in there. Suppose I'm rather lucky I didn't foul anything else up doing that, eh?
Anyway, thanks for the help, hopefully we've found the problem.