Power output voltage problem?

[feebee]

I am having a problem with the output voltages on my new system.
Specs:
AMD athlon 850
Asus a7v133
256 Mb
300 Watt power supply
The problem is that the output voltages (as measured by my Asus utility that came with the MB) are not always constant.
Usually the +3.3V is actually +3.6V
Sometimes +12V drops to +10V
Usually at startup +5V is +4.3V (as indicated by BIOS hardware monitor)
Lately there's also an unusual noise when booting, I think it's coming from the CPU fan.
My system will boot up however and there are no stability problems or something like that when running.
Is this something to worry about or am I worrying too much?
Any advice/comments are welcome.
Thanks in advance

[bassvax]

Those values reported during the monitoring can be set to provide an alert...but...read the following excerpt from Scott Mueller's Upgrading and Repairing PC's 12th Edition regarding Power Supply Specifications

Load Regulation (or Voltage Load Regulation)

When the current drawn from a particular output increases or decreases, the voltage changes slightly as well, usually increasing as the current rises. Load regulation is the change in the voltage for a particular output as it transistions from its minimum load to its maximum load (or vice versa). Values, expressed in terms of a +/- percentage, typically range from +/-1% to +/-5% for the +3.3, +5, and +12V outputs.

Overvoltage Protection

The trip points for each output at which the power supply shuts down or squelches the signal for that output. Values can be expressed as a percentage (for example, 120% for +3.3 and +5V) or as raw voltages (for example, +4.6V for the +3.3V output and +7.0V for the +5V output).


So, I would say you don't really have a power supply problem at this point. As I said you can set the percent variations to your liking to warn of problems...I would recommend researching this on the ASUS site (I know it is painful as I have the same mobo as you).

As to the noise your are hearing...is this a new noise? Some folks with this board report problems with the cheap fan over the chipset and have gotten replacement fans from ASUS. Definitely monitor the sitaution as you can easily fry your processor if that fan-heat sink combo fails. Try running your system with the cover off for a while to see if you can determine the noisemaker.

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Edit: Another thing to consider is getting an AMD certified power supply as they (AMD processors/boards) seem finicky that way.

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[This message has been edited by bassvax (edited 07-04-2001).]

[yawningdog]

The two problems could easily be related. If the fan is stiff or sticking, then it is certainly going to draw more current from the power supply and some power supplies will drop voltage as a result of the extra load. Fix the fan problem and I bet your voltage problem will go away.

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He thrusts his fists against the posts but still insists he sees the ghosts.

[Reid]

I think you would be having serious stability problems if the voltages you are reading are accurate. None of the voltages are within +/- 5%. I'm fairly certain that most 5V logic circuits would not run properly at 4.3V, and 3.6V going to the CPU I/O should cause a CPU to be very hot.

This link (http://www.dansdata.com/fanalarm.htm) says that a stalled brushless fan will draw about double its normal current. Typical power supplies provide about 10 or 12 amps on the 12V output, and would be unaffected by the increased current draw.

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reido@my-deja.com

Friends don't let friends install Windows ME

[This message has been edited by Reid (edited 07-04-2001).]

[mjc]

Since you say that you do not have stability problems then I would suspect the reported voltages...the reporting program may be wrong...also check to make sure that there isn't a cable or cord hitting the fan blades.

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mjc
Links list:Computer Links (http://www.fortunecity.com/skyscraper/highrise/11/index.htm)

Celts are the men that heaven made mad, For all their battles are merry and their songs are all sad.


[This message has been edited by mjc (edited 07-04-2001).]

[Rick]

feebee

The program you are using to measure these voltages as supplied by Asus.
Is that program by chance (Probe) If so that is part of your problem.
That program is well known to be in-accurate .

I also have the A7V133 and have found that Probe is just about worthless.
Showing my CPU and System temps off by 10 to 15 degrees each. ( Higher)
Then they were in the Bios or using other Monitoring Programs.

I would suggest you check out MBM5 ( Mother Board Monitor) http://mbm.livewiredev.com/

Believe what the Bios is telling you. Not the Asus Probe Program

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To ERR is HUMAN
To REALLY screw things UP, YOU NEED a COMPUTER !

[Randy_tx]

The Bios should have a window which will tell you what the RPM's of the cpu fan are.........for an Athalon, you really need rpm's of 5-6,000 or more to achieve good cooling. I have a dual fan on my Athalon that runs at about 7,000 rpm's for example. CPU temp hovers around 100 deg. F.

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Will XP save Me ?

[spaceAlien]

This is probably not something you want to read while eating lunch, but I once had a big clump of lint/grunge come loose an strike the fan blades and it made a surprising amount of noise....



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[feebee]

Thanks everyone for your replies.
I've dowloaded the Motherboard Monitor Program.
It's shows the same values for all voltages.
To specify what's going on:
When I perform a cold boot, the monitor won't turn on, I just get some lights from the HD. Then I have to press reset and the monitor will turn on.Then I get an error message from BIOS saying:
"Hardware monitor found an error, press F1 to continue, press DEL to enter set up"
When I check the hardware monitor in Bios the +5V is usually around +4.3V
After reboot, it still gives the same error, but if I press F1 to continue, load windows and check the Motherboard Monitor, the +5V will be higher (for example currently +4.49V with system on for about 10 minutes).
Sometimes the values will return to a more or less normal value, except for the +3.3V, which is usually exactly +3.62V and stays there.
The noise at boot up is definitely coming from the CPU fan, but disappeares after about 5 to 10 seconds. The reported RPM for the CPU fan is about 5000. The temperature for the CPU is about 131 degr. and the MB 109 degr.

Any thoughts about this? I have to say that I'm definitely not used to working with the fan/heatsink, so I should probably return it to the store anyway. But maybe there is something I can do that's fairly easy.

[mjc]

Well if both programs are giving about the same results then you possibly have a power supply or regulator probem and if the systemn is still under warranty then get the store you bought it from fix it....

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mjc
Links list:Computer Links (http://www.fortunecity.com/skyscraper/highrise/11/index.htm)

Celts are the men that heaven made mad, For all their battles are merry and their songs are all sad.

[bassvax]

Sorry, I forgot to mention the unreliability of the ASUS Probe utility...I'm glad you took Rick's advice regarding Motherboard Monitor.

I agree with MJC here...and while you're there have them replace that CPU fan for you as well http://www.PCGuide.com/ubb/smile.gif

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Flush 'N' Forget
FE Stokes WWTP (http://www2.apex.net/users/hwuswtp)