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Possible power supply problem

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May 7, 2006 6:27:46 PM

I built a new system back in February and have encountered alot of difficulty with it. I have finally got most of it worked out but have now experienced yet another problem.

When playing 3D heavy games for any length of time I start to notice graphical errors. Black jagged triangles shoot all over the screen. They get worse the longer I allow the game to run.
At first I thought it was a heat problem, the system has always ran hot but never enough to cause serious concern.
Temps will hit 145 for the CPU and 160 for the MoBo but quickly cool down after I am done with a game session. All of my components stay well under slowdown/shutdown temps so I am ok there.

But after one bout of this problem I opened my Asus probe utility and discovered an error.
My +3.3V was off and the audio alarm sounding. The voltage was down around 2.6-2.7 V
After several minutes it would creep back up to 3.2 and 3.3V

So now I have some questions.


What is 3.3V and what does it do?
Is this my problem?
How can I fix it?


Thanks in advance for any help

More about : power supply problem

May 7, 2006 7:08:02 PM

I am curious what your mobo model is, and I wonder if your gpu is heating up all the same...

I would say try to crack the lid, get a big room fan (box or oscillating in stationary mode) have it blow air directly in the open-lid case and try and keep the temps cool while gaming - it may solve your problem - 160 is really hot for the mobo voltage regulators, may be related to the voltage sag and the gpu overheat may be the cause of the graphic errors...
May 7, 2006 8:04:59 PM

We need details before a diagnosis can be done. What is the rated power of your power supply, what CPU do you have, what graphics card, what motherboard? The power drop seems to indicate that the PSU is being overtaxed, so its total power drops until everything else stabilizes, so you may need a bigger unit. The temperatures are high for your CPU and motherboard, which means that you need better cooling; more fans, bigger heat sink, or both.

The reason that your graphics get worse as time goes on also is probably because of overheating, but can also be caused by not having enough power, or both.

Heat is the big enemy of computers, and lack of power the next on the list. I run 5 fans in my computer and have tempts around 40 centigrade under full load, never yet going higher than 43.
Related resources
a b ) Power supply
May 7, 2006 8:05:02 PM

Not sure what the 3.3v rail is used for. In a modern Power Supply most of the power is drawn from the 12v rail. Some PSUs uses both the 5v and 12v rails to deliver power to hard drives and CD/DVD drives.

Maybe the 3.3v rail powers the floppy drive. I really don't know.
May 7, 2006 8:20:55 PM

Asus A8N32 SLi Deluxe

Athlon 4000+ running at stock speeds
Zalmann 9800 heatsink running over that

Two BFG Geforce 7800GTX cards overclocked but they came from the factory that way

Thermaltake 680 watt PSU

Three 750 GB WD 16mb cache 7200 RPM drives running in Raid 0

Two 8mb cache WD 80GB 7200 RPM drives running in Raid 0 for backup


There is not really much I can do about the heat. I have 7 case fans running on top of the fans built into the components and the big Zalmann heat sink.
I do not really want to dwelve into liquid or refrigeration until my next system.


I contact BFG and Asus and they said while temps were high they were acceptable and the parts could function under those temps for many years.
May 7, 2006 9:49:33 PM

Now that I know your system, my guess is that either your PSU is faulty or you just plain need a larger one to power all those hard drives. They are putting quite a strain on your system. The hard drives are also contributing a lot of heat. I have a fan blowing air across each of my hard drives. Don't know how yours are laid out, but its something to think about. One other thing to consider is to put a few hardrives in a separate case and running cords between them, something like an external hard drive. That should lower the main case tempts.

Another thing is to check out the motherboard carefully. I have the same board and after having some undefined problems for a month, it failed. I RMA'd it and am waiting for the new one now. Though I've had good luck with ASUS boards in the past, I've read that they are having quality control problems now, and my board's failure seems to confirm it.
May 7, 2006 10:20:29 PM

Quote:
Now that I know your system, my guess is that either your PSU is faulty or you just plain need a larger one to power all those hard drives. They are putting quite a strain on your system. The hard drives are also contributing a lot of heat. I have a fan blowing air across each of my hard drives. Don't know how yours are laid out, but its something to think about. One other thing to consider is to put a few hardrives in a separate case and running cords between them, something like an external hard drive. That should lower the main case tempts.

Another thing is to check out the motherboard carefully. I have the same board and after having some undefined problems for a month, it failed. I RMA'd it and am waiting for the new one now. Though I've had good luck with ASUS boards in the past, I've read that they are having quality control problems now, and my board's failure seems to confirm it.


I never imagined 680 watts would not be enough 8O

I also did not realize HDDs sucked up alot of power. I hope the PSU is not breaking down on me, that would be a pain in the ass to replace.
May 7, 2006 10:57:34 PM

Quote:
Three 750 GB WD 16mb cache 7200 RPM drives running in Raid 0


Is that a typo?
May 7, 2006 11:39:51 PM

Quote:
Three 750 GB WD 16mb cache 7200 RPM drives running in Raid 0


Is that a typo?

Yes, should read 250 GB not 750 GB :oops: 

But....
It was the best decision I made on this new system. My HDD scores are mind blisteringly fast and my friends with 10000 RPM Raptors hate me now since they spent more money for less storage and I get almost or just as good scores as they do.
I get uncached speed scores of 161mb/sec
May 8, 2006 12:19:55 AM

Quote:
I get uncached speed scores of 161mb/sec


That's blistering!
May 8, 2006 12:49:41 AM

It's possible that the OC'ed video cards are your problem. Even if they're OC'ed factory, it could be bad silicon. Are you sure nothing else is overclocked?

Really, though, it sounds like a bad capacitor, probably on your power supply. When caps get hot, they tend to work inaccurately if they're poor quality, old, or defective. When the cap cools down, it goes back to normal. I'm surprised you don't blue-screen when your volts on your 3.3 go that low.

Anyway, get a multi-meter. That's the best way to find out. You can get a ghetto one from Radio Shack fairly cheap (Cheaper than a new PSU anyway).

http://www.driverheaven.net/guides/testingPSU/

^^^ Use that. You can short a couple of lines on your ATX MOLEX plug to test it while it's not on the motherboard (I forget which ones, but my good friend google will tell you if you ask nicely ;) ). Pull your PSU as soon as it gets hot and test if off of the mobo. If it's showing a drooping 3.3 rail still, then replace the PSU. If the voltages are good while disconnected but faulty when the comp is powered, it's probably a faulty motherboard PWM, or a device that's draining WAY too much juice. You can get a wattage meter on ebay pretty cheap if you find it's not your PSU. If it's not your PSU or PWM, my money's on the video cards: those are known to be power hungry and HOT.
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