Voltage Flucutation

[hkopper]

I have a Asus P4P800 MB and I've been getting flucuations on the 3.3V indicator (asus probe). The flucuations range from as high as 3.7v and as low as 2.8v. It starts to occur right after playing about 1 hour or more of a graphic intensive program and is resolved by shutting down and restarting.

I changed the ac unit once and the mb twice but problem persists. The only thing that I can think that's to blame is the video card but can it cause these flucuations? The video card is a nvida ti4400 and the fan is working. The CPU and MB temps are normal as well.

Any suggestions?

[Jason425]

prob the PSU.. it's overheating and/or can't handle the load you're giving it..

[hkopper]

Excuse my ignorance but what is a psu?

[Jason425]

the power supply

[hkopper]

The power supply was replaced 350W to new 400W unit. The motherboard was also replaced twice.

[Jason425]

it COULD still be the psu.. what haven't you replaced?

[hkopper]

The video card

[Jason425]

try a friends card

[hkopper]

I tried another card and the fluctuations persists. I'm going to try running the motherboard outside of the case and with the bare essentials in terms of hardware (video card, hard drive, memory and PSU) to see if the same occurs ..maybe its a short in the case. If the problem persists, its safe to assume that the culprit is the PSU ...what would you recommend as a good psu?

[Jason425]

the antec trupower series is well known as a good pick...

enermax also makes decent, quiet psu's..

pc power and cooling make the best, but they're the most expensive. generally, you get what you pay for.

[eviltechie]

enermax arent really quiet
zalmans are the quiet ones
infact, i had to do a lot of mods to my enermax to get it quiet down and i still cant hear it...

there is OCZ powerstream if you are into tweaking out the best voltages for your setup

the thing is 3.3V does not come directly from the powersupply
it is converted in the mobo from other rails

so i really dont know what to say
the system instability could be due to other problems

[Jason425]

yea.. the antec is supposed to be quiet but when my CPU fan is turned down the psu is the loudest fan in the comp..

[vee_ess]

Definately get an Antec. Enermax is good, but I'd say they aren't in the same class, personally. The TruPower's have the truest ratings of any (ie. other "500W" can handle 500 watts but only for limited periods of time, not a true continuous 500...)

With any power problem, the problem will be one of three things: the motherboard, the PSU, or the power source...

[Jason425]

i think the mobo is underrated when considering power problems.. but us leet haxors buy top notch mobos most of the time so we don't realize it...