Pc Problem - This one's got me stumped

I do have a lot of exprience building systems and I know the basics about trouble shooting them, but this one is got me stumped.

I got a new CPU and video card for my gaming PC. Went from a core 2 duo to a core 2 quad, 2 gigs of RAM to 4, and from a 8800 GT to a 9800 gx2. I did not re-install the OS.

What’s happening is that the PC will restart suddenly, and randomly.

It doesn’t appear to be an overheating issue. I have the case panel off, and monitoring my temps, they never get above concer levels. My GPU’s will hover around 50 C and my CPU at around 45-50 C.

I also tried stress testing the CPU and RAM and the vidoe card. No problems were detected. I also checked the RAM using windows vista’s utility and again, no problems.

Also, there is NO blue screen. I even disabled windows autostart and I still get no blue screen or minidump. This led me to believe it was PSU problem, only I tried three different ones, and still, the same problem. I’m running vista SP 1 and the latest nvidia drivers.

Anyone have any idea what it could be? Could it possibly be that I didn’t re-instlal the OS? Perhaps something in this install is just not compatible with the new hardware? But if so, wouldn’t I get a blue screen?

I had this exact same problem with a TV card and Vista on my TV computer. I never did figure it out. I broke down and went back to XP. (Not saying you should do that).

I had this exact problem following an upgrade once. It turned out that one of the RAM modules was loose. Double check that all of the components are connected securely.

You said you were monitoring your temps and that they are okay. But I feel obliged to mention that I did once hear that leaving the case open isn’t a good way to keep the temp down becuase your airflow get’s screwed up. When I’m concerend about overheating, and want to leave the case open to help keep it cool, I usually set a fan (like a room fan) infront of the case to keep a lot of air moving though it.

But like Rysto mentioned, make sure everything is seated properly.

I think the first places I would be looking in a situation like this is the RAM, The Main board, and the re installation of the OS.

Go with resetting all of your BIOS settings to default first (assuming you made changes since before you installed the new hardware). the very latest release of your BIOS update would be my next guess. Barring that, I’d check online to see if there are any compatibility issues with your new RAM and your main board.

Also, Vista has this weird hardware monitoring scheme setup to combat running the same licensed software on different hardware builds. Their could be a bug in that. In this case, I’d recommend reinstalling the OS. I like to do that anyway when I make significant hardware changes.

Let me know how it goes.

Random restarts usually means power supply, or memory issues. You already ruled out the PS, so I will third the suggestion to check your memory. Make sure it is seated in the slot. Also try rearranging the DIMMs, that sometimes helps.

Power supply
Ram
then the OS.

I am not a tech but that is a truly classic power supply problem, with that set up I will take a wag and say absolute minimum you want 600w and honestly you should go for more.
I realize you tried several ps’s but if they were all to small in output then you will get the same error.

and dont skimp on a ps, a good one will last you a very long time and give you no hassles.

ram is famous for random errors. and I mean random frustrating piss you off to no end cant figure it out for any damn reason errors. while random shut downs are often along those lines ram errors are rarely limited to just one thing which is a give away, when your computer starts acting possessed its probably ram.

if both of those fail then wipe the hard drive and reinstall every thing from scratch (back up EVERYTHING first)
I have found a nice wipe works wonders and relieves all worries about everything else.

Is the RAM 2 sticks or 4? Some motherboards can’t run 4 sticks as fast as 2, so drop the speed and see if that helps.

I’d bet on the motherboard. I’ve seen many cases of flaky behavior that were solved by updating the motherboard’s BIOS or installing a better motherboard.

I’m going to echo everyone else here. What is your PS rated at? You’ve basically doubled your power requirements from your previous build, so be absolutely sure it’s not that.

Your 9800GX2 may also be the source of your crashes, or rather, the drivers. You mention you’ve got the latest so it may not be the issue.

I’d say format/reinstall Vista. You’ve made some big hardware changes and that may have messed with things. Besides, I can’t imagine how fast Vista is going to run on that rig you’ve built yourself.

green with envy

Has he, though? He tried different ones, but if none of them are supplying enough watts, then it’s not going to matter. I imagine the 9800, more RAM, and quad core CPU will all eat more juice, so if the PS can’t keep up with the demand, it won’t matter if it’s otherwise fine.

I was thinking the same thing. If he’s got a bunch of 300 watt PSU’s, none of them will work.

Might be something as simple as a bad power connector on the mainboard.

The quality of the PSU is also important. This PC is running 2 HDD, a dual-core cpu, a DVD, two fans, and a 8600GTS on a 250W PSU. And I reckon I come pretty close indeed to 250W when playing games. Plus the odd USB device.

According to Dabs.com you require at least a ‘580W PCI Express®-compliant system power supply with a combined 12V current rating of 40A or more (Minimum system power requirement based on a PC configured with an Intel Core®2 Extreme QX6700 processor)’. Note the secondary requirement of 40A: it’s not simply good enough to have a 580W PSU.

If the OP doesn’t have an appropriate spare PSU, then simply plugging the 8800 GT back in should provide an alternative test.

Jumping in - I agree that the PSU is likely underpowered for the new system components.

Thanks for the comments and suggestions so far guys!
I’ll come back tonight with the specs fo rthe PSU’s I tried. I know one of the ones I tried was 650 watts SLI ready, and the one in now is either 750 or 850 watts, I’ll have to check.

I left the Pc running this morning. It’s encoding 10 video files AND playing the first episode of ROME over and over again. I wonder, will these things till be running when I get home?

You could have had a power supply problem that ended up burning out a component in your motherboard. If you do end up replacing the board, I’d suggest testing the voltages on your power supply before reconnecting it.

Another good test for flaky hardware is to start by removing things and then adding parts back in one at a time with enough time in-between to check stability.

For example if you’ve got two sticks of RAM, pull one of them out and see if everything suddenly gets better. Then switch them, then put both back in - at what point do random restarts kick in?

Put your old video card back in and see if the problem goes away, etc.

I saw some statistics that showed that nVidia and ATI drivers were one of the leading causes of problems under Vista.

Well I got back home and none of the stuff that was running was still running. So the computer restarted :frowning:

Here are the specs on the two PSU’s I tried and tested under:

The one in now:

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=3438609&CatId=2533

I’m going to try removing each one of the ram sticks and see if that is indeed the problem. Man this is driving nuts.

Burn yourself a memtest cd and boot to it, if it comes up clean, ew.

If you have any other hard drives laying around (you sound like the type who might) try pulling your current drive out and doing a clean install of vista on a different drive and see if your reboot problem goes away. That way you can isolate for vista without screwing up your existing install. If you do a clean install of vista and the problem goes away you have an unrelated software problem or conflict with an old driver.

I have also seen random reboots be evidence of hard drives on the way out.

Is there anything about the reboots that you can tell us, always after an hour or so? Only when certain apps open, anything consistent about them?