It's on now and has been running for a while without any problems.

I thought it might be the power supply. Actually, I hope it is that because that's easy to replace and relatively cheap.

Here are a list of things that I have checked:
all the fans come on
all the voltage levels are within range
all the temperatures are within range

I used Intel Desktop Utilities to check this out.

Any ideas? I know it's kinda vague but that's all I have to go on. If there are any tools that can be used for diagnosing hardware faults that you can recommend, I am all ears.

There are no messages in the Event Viewer logs and I don't get any messages when the machine dies, it just plain switches off.

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I'm running memtest+ just now even though I am sure it's not a memory problem.

I was also watching the voltages and temperatures to see if I noticed any spike or general weirdness but didn't see any of that. I'm wondering if the PSU could be overheating and that's what's causing it to switch off. For some reason I'm sure it's not related to any of the other components.

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check on those
especially powersupply

make sure the fan on ur gfx card still works

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Everything seems to work just fine except for the reboots. I'll need to configure Intel Desktop Utilities to log all the system summary information so I can check it the next time it reboots. If it does that is.

UPDATE: memtest+ completed two full scans in about 80mins. No reboots. I'm back on my "faulty" PC with Windows running, let's see how long it lasts before rebooting again.

[ 07-15-2006: Message edited by: Mad Max ]

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If you have one laying around, you should try substituting a known good power supply and see what happens.

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“I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.”

“Intelligence is the ability to adapt to change.”

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“I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.”

“Intelligence is the ability to adapt to change.”

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I didn't do anything much inside of the unit and I didn't dislodge any dust, nothing that was noticable anyway.

Today I swapped out the power supply. Got an antec True Power 2.0, 430W from CompUSA. It's supposed to be $100 but with all the rebates it was only $40. So, if this works, then at least I have a PSU with 80W more power. Difficult to tell whether this is the solution though since the reboots were pretty random. I just have to wait and see. I guess if the problem persists it's likely to be a motherboard issue but I'll just wait and see what happens.

Thanks for the help, guys!

EDIT : to answer your question, Willy. The reboots seemed random. I mean, this morning I came downstairs and the PC was off. It was on last night and it wasn't doing anything. At night it's a bit cooler too so I would expect heat to be less of an issue at night than during the day. For cooling I have a fan on the cpu, a fan on the video card, a large case fan and a side case fan that is directed at the cpu. The PSU also has a fan.

[ 07-17-2006: Message edited by: Mad Max ]

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“I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.”

“Intelligence is the ability to adapt to change.”

Snaggles ~ I didn't notice anything but then I didn't look too carefully. Next I am in there I will check it out.

One "annoying" feature of the new power supply seems to be that it controls the speed of the CPU fan somehow. Now my fan idles at about 1000rpm but when my CPU is busy it spins up way higher than that. I can't say exactly how fast it's going because every time I go to check, the the fan slows down again. For example, playing Hit Man Blood Money, the CPU fan speeds up but when I shut it down and open up Intel Desktop Utililites, everything has calmed down. Now why is this annoying? The noise the fan makes when it's at full pelt. It's not a bad noise, just louder than I am used to.

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The heat thing is just a good first guess with those kinds of problems. It's really common and easy to fix. Power issues can be a little harder to diagnose and will often present more than just random reboots (I've had a few computers that lacked adequate wattage, and they would have to startup twice. They would boot and then reboot once almost instantly then continue to post and load fine after that. My theory was that the fans and hard drives were overdrawing current but that once the first kick started them spinning, there was enough juice run.)

If the PSU doesn't solve the problem, the next thing I would do is start removing or swapping out components like cards and fans and RAM modules and seeing if it runs alright. Reinstalling windows is another option that might be high on the list of most techs, but I personally hate to have to do that just because it's such a PITA to get everything reinstalled and reconfigured. Plus, it's not too highly likely that a software problem is the root cause here (though it is a distinct possibility. Maybe try grabbing all the newest drivers for your hardware and all the newest runtime packages and updates as well.) So ruling out power and heat, IMO the next likeliest thing is damaged or malfunctioning hardware Overheating video cards can cause reboots, but you'll usually have screen corruption or notice a correlation between heavy activity and stability problems. Ruling that out, blown out electronics these days rarely have any external presentation of damage so other than removing or swapping pieces one at a time, there's no sure-fire way to diagnose that I know of.

I hate to say it, but it really is starting to sound to me like it might be a mainboard or cpu problem.

[ 07-17-2006: Message edited by: WillyTrombone ]

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I could be your power supply ratcheting up as load increases (as it would while gaming).

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“I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.”

“Intelligence is the ability to adapt to change.”

quote:

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Originally posted by AcidWarp:
I don't see how the psu could control the CPU fan like that. Maybe pop the side off and take a look see under varying conditions.

I could be your power supply ratcheting up as load increases (as it would while gaming).

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It's definitely the CPU fan. I did have the side off and I watched all the fans while idle. I then started the game and heard the fan speed up. This is not something I would do ordinarily but I stopped the fans manually one at a time until I determined that it was the CPU fan spinning harder.

The PSU that I got is supposed to be a smarter one - whatever that all entails. Another difference is that it has ax12 connector to my motherboard whereas the old supply had only a 2x10.

Here is a line from the spec of my PSU:
"Fan Only power connectors allow True Power to control case fan speeds, reducing total system noise" -- however, my CPU fan is connected directly to the motherboard so I don't know what the PSU can do to affect it. I will write to Antec and see what they say.

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As an aside, I have a similar problem with my Dell here at work all because of an incorrect heatsink! I would be running a test that put my PC under heavy load and the fan would SCREAM!!! sometimes even after the test had completed. New heatsink, problem sorted. All the cooling hardward that I use on my rig at home is the stuff that was packaged with my purchases i.e. no adhoc cooling (although I am thinking I may upgrade my cooling since our house can get pretty hot during the day and my PC is stuck under a desk where airflow is not optimal - no other place for it to go).

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What is Intel? Precision Cooling?

Intel® Precision Cooling automatically adjusts the chassis fan speeds depending on the system's temperature. This feature reduces system fan noise by lowering the speed of the chassis fans connected to the front and rear chassis fan connectors. The processor fan connector is not controlled.

Interesting because something is changing the speed of my fan.

Edit: I am going to have to verify again that it is the CPU fan that is speeding up. I am sure it is but all this conflicting information is making me question my sanity!

[ 07-18-2006: Message edited by: Mad Max ]

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I checked to make sure the current assembly is tight and it feels like it is. I was concerned that maybe I dislodged something when replacing the PSU. Maybe the CPU fan is running fine but now it's just noiser than before. Seems like a strange coincident to me though. What rate does your fan spin when the CPU is loaded? I never used to notice my CPU fan making any noise at all but now I do. Right now it's 1600rpm and quiet as a mouse. Now it just spun up to 2100rpm and the mouse is a little less quiet. When I disable fan control in the BIOS the fan is locked at about 4000rpm and I can barely hear myself think. That's an exageration but I know for a fact that when I've been playng scary games in the wee hours that there wasn't a constant fan whine in the background. Maybe it's time to build a new PC? After all this one is almost 12 months old!

[ 07-18-2006: Message edited by: Mad Max ]

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The noise is also definitely new. I play some games where you need to sneak around and listen for things which I can't really do as easily now. Actually, I'm surprised I can sneak up on anyone the racket it makes.

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quote:

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Originally posted by GFKiller:
You should be able to disable the "Smart-Fan" feature for the processor fan in the BIOS. Just shut it off all together.

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I did that already (keep up, GFK - see above ) but that just meant the fan stayed at 4000rpm (loud). I got a new fan yesterday, a Zalman 9500 and now my rig is quiet again and running 30 degrees cooler.

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I like the smart-fan feature, then again my CPU Cooler never gets loud to begin with (even at full blast).

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“I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.”

“Intelligence is the ability to adapt to change.”

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quote:

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Originally posted by Mad Max:
I did that already (keep up, GFK - see above ) but that just meant the fan stayed at 4000rpm (loud). I got a new fan yesterday, a Zalman 9500 and now my rig is quiet again and running 30 degrees cooler.

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Hehehe, I tried to keep up, I really did! LOL