Sensors reporting incorrect values

[GhOsT1321]

For the past year or so I have had trouble with any sensor monitoring program reporting incorrect values.
An example, my 12 volt rail is always reported as 5.xx volts. When I had my old Thermaltake power supply, it too had a reported 12 volt rail of 5.xx volts.
I am pretty sure that any volts under 10 and my computer would not even turn on, so these voltages must be incorrect.
What causes this?

I am not sure if it's related, but today when I was running Prime 95, my Motherboard temp was 40, and my CPU temp 48. All of the sudden, CPU temp disappears, and Motherboard temp is listed as 60. No sooner than this occurred, the temps were back to normal and CPU temp reappeared.

Here is a SS of what my sensors are reporting as I am running Prime 95.

 

[Slaymate]

It sounds like defective mobo circuitry.

 

[GhOsT1321]

Do you believe that a BIOS update would help any?
Could the defective mobo circuitry cause any problems other than incorrect values?

 

[Slaymate]

Do you believe that a BIOS update would help any?

Probably not but if a newer bios is available it maybe worth trying

Could the defective mobo circuitry cause any problems other than incorrect values?

In my experience when one problem arises more are not far behind. But you never know.

 

[Digerati]

Wait - this totally unrealistic +12V value is a trend I am starting to see - including on my own system - on several systems. And you are right, the system would not work properly if the voltages are off that much.

Are you running Windows 7? It seems to be related. Check your voltages in your BIOS - are they off there? If good in the BIOS (as mine are), then that indicates a problem with how these sensors are interpreted in Windows since the BIOS readings are before any OS installs.

 

[GhOsT1321]

I'm running Windows 7 Home Premium 64 bit

The BIOS is reporting great voltages.
3.3V - 3.344V
5V - 5.061V
12V - 12.144V

I'm glad that there isn't an issue with my mobo, an RAM to MSI would be a PITA considering that this is my only windows computer.

Thanks for the suggestion!

 

[Digerati]

Good! Sadly, several folks have bought new PSUs only to find out this was just a sensor issue, and not a voltage issue, and the new PSU reported the same bad results. I glad you got yours sorted out before it got to RMAs.

 

[Slaymate]

While the voltage readings in the bios are good, none of the components are experiencing any type of a load, so the numbers could drop dramatically or they could stay stable. Most manufacturers offer there own Windows based monitoring utility for there motherboards, check the CD that came with your mobo.

Your Temperature sensor readings have nothing to do with your Voltage sensor readings, unless a sudden voltage drop under load reduces the sensor's operating voltage.

I still think it's probably a problem with the mobo's sensor circuitry, but I'm just guessing.

 

[Digerati]

I still think it's probably a problem with the mobo's sensor circuitry, but I'm just guessing.

If this were an isolated case, I would agree with that. But it is not. As I noted, I have seen several cases where the +12V was reading dramatically and unrealistically low. At another forum where I am on the Tech Team, we (other techs) have a running thread on the discussion with at least a couple dozen examples where the computers are running perfectly fine, but +12V is seen as drastically low - all with Win7, BTW.

Sorry, but it is not true that voltages in BIOS are not under load. If the PSU is connected to the board, there's a load. And if the computer is running, even in the BIOS, the fans and drives are spinning, the CPU and RAM are "live" and running, as is the graphics solution, drive controllers, etc. There is a very real resistive "load" there.

Temperatures, on the other hand, are different. Running the BIOS Setup Menu is about the least demanding task we can ask of our computers. And so temperatures in the BIOS are likely to be lower than when the computer is running Windows and doing "real" tasks.

I also agree to use the motherboard maker's monitoring program, but I note it too will run under the OS, and it will use the exact same sensor devices and any other monitoring program.

And if this is a Windows or W7 problem, it will not make a difference - as is the case with me. I note my PSU +12V measures +12.32V with my multimeter when connected to the motherboard and running Windows. The BIOS shows 12.2V, as does my FrozenCPU Ultimate PSU Tester. However, all Windows based HW monitors are showing 5.6 to 7.1V.

So at this point, I think it is a Windows problem, and not a hardware issue as I note in a couple of those examples, voltages were good with XP or Vista, but not after upgrading to Windows 7.