Hi there,

I´m having a problem when using Everest and Speedfan, related to the reading in the 12V rail. I get very strange numbers like 1,5 or 3 (!). However, in the Bios menu, this reading is perfectly normal (12,1).
Wich reading should be considered trustworthy?

While working or gaming with the computer, i don´t experience any kind of problems.

Best regards,

You're kidding, right?

Obviously, the BIOS is doing a more accurate job of reporting what is happening. If your 12 volt rail WAS down around 3 volts, or even 6 volts, your PC would not boot.

You can use a multimeter to double check what your BIOS is telling you.

I apologize. I have more than 30 years experience with small computers going back to when "building" meant taking soldering iron in hand and 45 years total electronics experience. I occasionally forget that what I may regard as a stupid question isn't to the originator.

A better question to ask would be, "In a working PC, why does the BIOS tell me that my 12 volt rail is 12.1 volts, but Speedfan and Everest report 1 to 3 volts?"

^ lol

yeah. that was his question. why those two are reporting such things

No problem, thanks for the expertise.

It´s just that i had a damaged board on a previous system and the readings on the voltage rails then were absurd, with variations of over 50%. However, the only symptoms were damaged ram after a couple of months...
Glad to see i won´t have to worry about that now.

Sometimes some Bios versions give wrong readings too and you have to go back to a previous version to get normal readings.

I mentioned using a dmm to verify PSU voltages, then I realized that I didn't tell you how.

I extracted the following from my "Troubleshooting a New Build" article in Tom's Wiki (http://www.tomswiki.com/page/Troubleshooting+a+New+Build):

""Quick and dirty" under load PSU voltage checks (carefully, carefully) of the main outputs with DMM black lead grounded and red lead inserted into the back of the various PSU connector pins plugged into the motherboard:
yellow, yellow/black, and yellow/blue wires: +12 v
red: +5 volt
orange: +3.3 volts
blue: -12 volts
purple: +5 volt aux or standby - should be present if PSU plugged in and main power switch on
All readings should be +- 5%.

The PSU color coding is pretty standard.

The 5 volt Standby or AUX output is completely separate from the main outputs. So seeing the red or green LED on the motherboard does not mean that the PSU is good.

While we are talking about PSU's, if you have a suspected bad PSU, also check the grey wire on pin 8. It provides a control signal called "PwrOK" that the CPU needs to start booting. With the PC off, it should be at 0 volts. It should go to around 5 volts (anything over 3.6 volts will be OK) within .5 seconds after pressing the power switch. You can have all the power outputs present. But if you don't have this, your PSU is broke and your PC won't boot."

Thanks again for the help, jsc.