Sign in with
Sign up | Sign in
Your question
Closed

Low voltage readings with no affect

Last response: in Motherboards
Share
November 1, 2010 12:44:51 AM

Need some advice to put me at ease. This morning, I received a warning message after rearraging the cabling in my PC. It turns out that, according to the BIOS as well as several monitoring programs, that I have 1.06V for the 3.3V, 1.75V for the 5V, and 4.22V for the 12 V. I know that this isn't accurate because the system starts fine and passes any test I throw at it from Prime95 to Futurmark. I tried swapping out the PSU and even flashed the bios but I still get the low voltage readings. IT is an ASUS P5N32-E Sli motherboard.

So should I be concerned about this or just ignore it?
a c 435 V Motherboard
November 1, 2010 8:57:48 AM

Try a different power supply first. If you don't have a spare, now's a good time to get one. I always keep one handy for situations like this. Newegg had an antec 400w for twenty nine dollars after rebate, but it expired this morning.
Score
0

Best solution

a c 156 V Motherboard
November 1, 2010 9:10:14 AM

Obviously, because the system boots and runs, the PSU isn't that bad. Before you swap PSU's, verify the readings with a DMM.

Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.
Share
Related resources
November 1, 2010 10:56:59 AM

I'll give the DMM a try. I already tried swapping out the PSU (as noted in the origninal post) but it made no difference. I believe though, that if those voltages were in fact correct, the computer wouldn't even boot. Especially given that it has a 5770 video card. Without the correct power, the LCD wouldn't even come on (not enough power to the video card).
Score
0
a c 123 V Motherboard
November 1, 2010 1:24:34 PM

Thats ok my 12 volt shows as 0.77. There is no way that the system would run on those voltages.

Any power supply that is even half decent, will shut it self off when it falls out of spec. As said above, grab a meter and check away.
Score
0
November 1, 2010 4:21:06 PM

So, I take it then, that it is just a faulty monitor on the motherboard? In all the PC's I've owned (to many to count), I have never had that happen before. It can't be very common. I just hope that it isn't systemic, leading to other faults that are more problematic.
Score
0
a c 123 V Motherboard
November 2, 2010 2:33:10 AM

I have seen many boards with this issue(I have had many to play with).

Sometimes its just the way the sensors are read, I have not seen it in the bios however. It has always been with 3rd party software.

Did you get to check with a meter? I mean there is no way it would run with the 12 volt that low.

For fun, look at speedfan pics in Google. you will see lots with strange numbers.
http://www.google.ca/images?q=speedfan&um=1&hl=en&biw=1...
Score
0
November 2, 2010 9:44:49 PM

I have to buy a new voltmeter on Thursday. I will post back with the results.
Score
0
November 3, 2010 8:35:08 PM

5.09, 12.09, and 3.3 just like the doctor ordered. I can only assume that whatever chips(s) on the motherboard that are designed to monitor voltage are dead or corrupt. I flashed the bios and it made no difference. Problem now is that I have no reliable way to monitor my voltages any longer without using a volmeter.
Score
0
a c 123 V Motherboard
November 4, 2010 12:43:01 AM

In most cases its the same chip as the rest of the hardware monitoring. Most boards use chips from ITE. Since this is a separate chip, flashing the bios will not fix it.

I do not think it is a deal breaker, but if you are worried, you can contact your MB maker if it under warranty for a replacement of the board it self.
Score
0
November 4, 2010 1:01:51 AM

Replace the board, reactivate Windows (at the very least), down time, complaining kids. Nope. Think I'll take my chances. When / If she goes, its time to upgrade. Thanks for the advice. =)
Score
0
November 10, 2010 10:58:34 PM

Best answer selected by Timoty.
Score
0
a c 135 V Motherboard
November 11, 2010 11:26:10 AM

This topic has been closed by Maziar
Score
0
!