PSU & voltage increase?

[stevedownunder]

Hi All
I’m getting a bios warning about voltages.
I have P4 1800 with an Asus m\board, award bios.

Anyhow, the voltages should be:

+3.3v
+5v
+12

But they are reading:

+3.31v
+5.45v
+12.80v

There is an option to ignore the errors in the bios but I don’t know for sure if it will damage the mobo/cpu etc long term.

Any idea??


Steve

[FijiJohn]

Those voltages are PROBABLY(!) fine from my experience. (I've seen computers run for a long time like that.) However, I hate to turn off the alarm in case something major happens and the last time I had a PSU like that I replaced it. The cost of a good PSU (e.g., Antec) is just not that much. Peace of mind is.

[dajogejr]

I believe within +/- 5% is spec.

Someone correct me if I'm wrong...

Do you have the current BIOS for your PC?

What kind of PSU do you have?
Watts rated at?

Devices in your PC...

Antec, Sparkle, Enermax and Fortron all make very nice PSUs.

Here's a calculator to help you out.

http://www.jscustompcs.com/power_supply/

[stevedownunder]

I believe within +/- 5% is spec.
Hmmm I’m not sure myself.
It’s intermittent also sometimes OK sometimes not?


Do you have the current BIOS for your PC?
Bios was updated didn’t make any difference.


What kind of PSU do you have?
Powerman ???

Watts rated at?
300W

Devices in your PC...
CD drive only
(excluding vid, lan)


Actually it’s a works one and I’m debating whether to return it under warranty?


BTW why won't my siganture work if it's ticked to work?

[lptech]

stevedownunder-

I think that the reason you're experiencing some intermittent problems is because your PSU (Power Supply Unit) is underpowered and hiccups from the fact that you probably have too many items drawing on the 12-volt rail during POST.

Remember that Athlons and P4s all use the 12-volt rail and it shares it with all of the motor-driven components- i.e. FDDs, HDDs, CD-Rom drives, CDRW drives, DVD-Rom drives, case fans, etc. So when you first boot, they all draw maximum current from the PSU and causes the so called intermittent that you've described.

I would recommend getting a PSU that has ample power to drive your load on the 12-volt rail. 450-watts to 600-watts power rating would suffice nicely since you won't even be forcing your PSU to work too hard and that it should last longer. Good luck!

LPTECH

[stevedownunder]

Thanks for that,
steve

[ukulele]

The voltages should all be within +/- 5% except for the -12v reading which is usually +/- 10% for testing purposes. If you do the math you will see that the 5 volt rail is over by 9%. That should trip the warning but unless it fluctuates up and down a lot, I wouldn't be concerned. Circuits with a higher then spec voltage actually cope with variances much better then circuits with lower then spec voltages as voltages tend to drop a bit as the load increases anyway. I did a lot of security system installation and ac transformers are notoriously over voltage as they get older. It doesn't seem to hurt the IC chips till it gets 20% over, but more then 5% under voltage is not good.

[RamonGTP]

Could also be false readings... Best thing to do is check it with a meter.

You can run 3 of those spec PC's on a 600watt PSU... I don't think he needs anything THAT big.

[Strawbs]

I would say it may be losing it's integrity and personally would replace it, but not with a 600w model! that wouldn't just be overkill, it might possibly be murderous to a computer so lightly spec'ed.

I have a 500watt PSU because my case is full to bursting with components and lights, inc. 3x HDD, 2x Optical drives, full complement of Ram, 3x large fans, Card reader, PCI fan card, 9700pro, 2x LED temp displays, PCI modem, floppy drive and the aforementioned lights. I'm currently showing voltages of 3.39, 5.00 and 12.67. You have none of that, so 400w would be enough to give you some headroom for future additions without going OTT IMO.

[ukulele]

I would say it may be losing it's integrity and personally would replace it, but not with a 600w model! that wouldn't just be overkill, it might possibly be murderous to a computer so lightly spec'ed.

Not to worry. More is always better when it comes to power supplies. Just make sure it is going to fit in the case.

If it's not broke you don't need to fix it.

[Rabbitrunner51]

nowadays ...300 watts is a bare minimum...and I tend to think you need a better PS and more wattage.....

What all do you have hooked up to it???

In your bios..I believe under power..you can see firsthand the fluctuations if any...if they do not move much at all or not at all then you might be OK ..as there is a plus or minus on these for a reason... some devices are not all calibrated the same and would give differing wattage readings...

[lptech]

stevedownunder-

A 300-watt PSU is just asking for trouble at this point because you're forcing it to overwork and that is why it is running intermittent! Since the Athlons and P4s first came out the importance of having an adequate amperage available on the 12-volt rail became more and more important. Unfortunately, if you look at most of the power supplies manufactured today, few are setup to adequately meet the power demands on the 12-volt rail unless you're looking at 400-watts and up since at that point there would be enough amperage available at the 12-volt rail to supply the CPU and all the other motor-driven devices attached.

The other important factor to consider is the fact that when you run your PSU overloaded, it will eventually fail and possibly take along with it the some or all of the components attached to it (i.e. - motherboard, CPU, FDD, HDD(s), optical drives, etc.). Is it really worth the risk because you're running it on an inadequate PSU? I think that from an economic point of view, it is more frugal to buy a more powerful PSU, than to risk destroying the system. Good luck!

LPTECH

[stevedownunder]

I have it sorted now.
The supplier sent out another PSU.

It's only a 300w but I haven't had any more problems and the voltage is now stable.

Thanks
all

[Strawbs]

a 300 watt PS will be working too hard for too long to last any decent period! so we can probably expect to see you again in a few month's with a similar issue!

Until Then ...