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PSU voltage drop?





saratdear
Hi,

I have a software called Speedfan installed. It is a great piece of thing which shows fan speeds, voltages, temperatures, etc. and can even let you control fan speeds. Well, what I am getting at is, for 1-2 months I've been noticing a drop in my PSU voltages. The +3.3V is at 2.9, the +5V is at 4.92, and +12V is at 11.92 currently. I've seen a similar thread here and seeing that the OP there was advised that it was not much of a problem, I decided to leave it.

But when I run any stress testing program (like Prime95) the voltages drop waaay low, like to 2.83, 4.8, 11.43, etc. To top it all, I have a slight grinding noise coming from the PC nowadays, which is irritating.

Am I heading to serious trouble? Confused

Sarat

UPDATE : OK, I was checking out speedfan again, and is noting something strange. It has a CPU meter as well. Whenever it is at 0%, the PC is silent, but when it jumps to anything above 0%, the PC starts the grinding. Perhaps a coincidence?
Diablosblizz
I don't have an absolute answer to your question, but: Speedfan isn't always reliable.
saratdear
Diablosblizz wrote:
I don't have an absolute answer to your question, but: Speedfan isn't always reliable.

Oh..I've been checking the voltages in the bios everytime I boot up now, and I have found the voltages when idle (as posted above) to be more or less equal to speedfan. But I can't access the bios voltages when I am doing a stress test, so I can't say that for sure.
Diablosblizz
How are you accessing the bios when idle in Windows?
ocalhoun
saratdear wrote:
Hi,

But when I run any stress testing program (like Prime95) the voltages drop waaay low, like to 2.83, 4.8, 11.43, etc.

This is acceptable, and it is normal that when you put a heavier load on it, the voltages fall.
(The power supply can only supply a certain wattage, which is amps x volts. Putting a heavy load on the computer increases the demand for amps. In order to supply it, the voltage drops.)
Normal margin for error is around 10%. So, the 3.3 falling below 2.97 is slightly bad, but the other two are still well within tolerance, even at their lowest point.
Luckily, low voltages won't damage any components, and you needn't worry about voltages being too low until you have malfunctions (freezes, slowing down, or spontaneously shuts off).
If you do experience such malfunctions, or if you're inordinately worried about that 3.3V going out of tolerance, you'll have to replace the PSU. If you do, then replace it with one that has a higher wattage rating.
(Also, you could disconnect any superfluous peripherals (drives you don't use, et cetera). Doing so will reduce the power demand, and might bring it back within tolerance.)
(Also, check the input voltage from the wall. Below 105 volts, and I'd suspect the input power, not the power supply.)
Quote:
Whenever it is at 0%, the PC is silent, but when it jumps to anything above 0%, the PC starts the grinding. Perhaps a coincidence?

Clean out your CPU fan. If it still makes the noise, consider replacing it, because the noise might be a warning that it will fail soon, and if it fails without you noticing, your CPU could overheat and be damaged.
(The CPU fan is the only moving part in the computer that should be stopping and starting like that.)
pll
ocalhoun wrote:

Clean out your CPU fan. If it still makes the noise, consider replacing it, because the noise might be a warning that it will fail soon, and if it fails without you noticing, your CPU could overheat and be damaged.
(The CPU fan is the only moving part in the computer that should be stopping and starting like that.)

I had this bad experience with one of my old computer, everything was damaged except the Hard Drive Disk.
I heard somekind of strange sounds about a week before it crashed but I wasn't really thinking about it.
One day, I opened up the computer and I heard the same sound but it became louder and louder, and then I saw some smoke get out of the computer. It was the end. Embarassed

The technician said it was because the machine had too much dust in it (I had never cleaned it up).
Now I clean it up about one time a month.

Clean every fans in your computer!
saratdear
Diablosblizz wrote:
How are you accessing the bios when idle in Windows?

Oh..by "idle" I actually meant when it boots up, because of course I don't have any way of accessing the bios when Windows is running.

On second thought, the time of booting up isn't actually idle, right?

@ocalhoun - Since I'm not experiencing any malfunctions, I guess I'll just leave it here. And yes, I will try to clean the cpu fan, but I'm not exactly sure how to go about it. I've tried a lot of times, unsuccessfully to take off the CPU fan and it stubbornly remains budged. I have a Pentium 4 (pretty old, I know Smile ) and the only way I see of removing it is to shift two clip kind of things to either side, and it is supposed to come off. Except it doesn't.

Well, I've also seen many guides advising to oil the fans. I've not tried it yet, but do you think it will work?

I don't worry too much about the CPU overheating and dying. Because the Pentium 4 is supposed to have a feature which automatically shuts the PC off if the processor gets dangerously hot. Actually, I've seen it at work once on my own computer. Twisted Evil
ocalhoun
saratdear wrote:
I will try to clean the cpu fan, but I'm not exactly sure how to go about it. I've tried a lot of times, unsuccessfully to take off the CPU fan and it stubbornly remains budged. I have a Pentium 4 (pretty old, I know Smile ) and the only way I see of removing it is to shift two clip kind of things to either side, and it is supposed to come off. Except it doesn't.

Those clips are indeed a pain... I've damaged a motherboard once, and damaged fingers many times installing and uninstalling them. (You usually have to apply your full strength to a tiny little metal piece that could slip off easily, and is surrounded by sharp-edged objects.)

Look for screws (1) attaching the fan (2) to the heat sink (5) though. Most CPU fans can be removed from the metal heat sink part without undoing the clips (3).


Failing that, you may be able to clean it well enough without removing it. Canned air should be able to blow away the dust, and a light application of (non-flammable machine) oil won't hurt anything. (Oil won't harm the CPU or motherboard) You can also use rubbing alcohol (in light amounts!) to clean it, because it evaporates very quickly. (Make sure you wait until it dries completely before turning it on again.)
(If you use oil, do make sure it is non-flammable! The brushes in the fan motor can make tiny sparks, and if the whole thing has flammable oil on it, that could make your computer into a nice bonfire.)

Also, if you're able to take the fan off like in the picture above, you might be able to replace it with another standard-sized fan... Fans are usually cheap $5-$10, so it might make more sense to just replace it than to try to fix it
saratdear
Thanks for the advice ocalhoun. Thing is, as far as I can see, there are no screws. Wait...this page pretty much represents what I have to do - http://www.pctechguide.com/tutorials/Pentium4_Remove.htm

Although the advice given at that site is helpful, I don't really like the idea of sticking my screwdriver at various places, because I am scared I will damage something. So usually when I want to clean it, I just use a soft cloth to wipe out as much of the dust of the fan blades as I can, then use one of these nice hair paintbrushes to brush away the dust that has settled under the fan blades. (You know, the location where there are lot of long narrow holes which I suppose is to radiate the heat from the heatsink towards the fan blades.

EDIT: Silly, silly me...this is the reason why I am nervous about opening the PC's case. I decide to clean the CPU fan without removing it. Steps taken : Unplug everything. Remove case. Clean inside. Replace Case. Replug everything. Turn on the system.

What happened was, the fans started spinning and all, and I know the hard drive spinned up, but the monitor won't turn on. I don't think it was a problem with the monitor, though. For the next half hour, it was just rinse and repeat. Finally, it turned on though. Razz

This topic is having a strong tendency to go off topic, but any idea what that problem could have been?
Fire Boar
You probably dislodged the graphics card. Make sure it is firmly seated.
saratdear
Fire Boar wrote:
You probably dislodged the graphics card. Make sure it is firmly seated.


That's probably it...but my monitor usually shows a screen saying "No signal, Check cable" irrespective of whether the computer is on or not; so if it is not receiving signal it should show that right? I tried unplugging the signal cable to reinsert it and yes, it showed that screen. Well, whatever. It's only a minor bug, I suppose. Smile
ocalhoun
saratdear wrote:
Fire Boar wrote:
You probably dislodged the graphics card. Make sure it is firmly seated.


That's probably it...but my monitor usually shows a screen saying "No signal, Check cable" irrespective of whether the computer is on or not; so if it is not receiving signal it should show that right? I tried unplugging the signal cable to reinsert it and yes, it showed that screen. Well, whatever. It's only a minor bug, I suppose. Smile

So, that means it was getting a signal... a signal to display a blank screen. As long as the problem is already solved, though, there's no sense worrying about it.
Donutey
Just an fyi, if you don't trust the voltages in the BIOS or from a program, a multimeter is your friend.
saratdear
Donutey wrote:
Just an fyi, if you don't trust the voltages in the BIOS or from a program, a multimeter is your friend.

Thank you for that. But I thought I'd just leave it. I don't have a multimeter anyway. Smile
ocalhoun
saratdear wrote:
Donutey wrote:
Just an fyi, if you don't trust the voltages in the BIOS or from a program, a multimeter is your friend.

Thank you for that. But I thought I'd just leave it. I don't have a multimeter anyway. Smile

They're cheap, and a good investment for anybody who regularly works on electronics...
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