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Thread: Can I trust motherboard voltage readings ?

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    Default Can I trust motherboard voltage readings ?

    CPUID HWMonitor, HWinfo etc. programs read motherboard voltage values afaik. Because voltage values of BIOS and these programs are the same. So, can I trust them? How much error margin do they have?
    How to read PSU voltages with multimeter?

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    Default

    no
    because you don't know where it is measured and how thick the wire to the chip is and so on.
    So no, it usually is way way off.

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    Quote Originally Posted by jonnyGURU View Post
    I'm sorry. I forgot to search it first...
    Thanks for sharing the topics.

    Quote Originally Posted by Stefan Payne View Post
    no
    because you don't know where it is measured and how thick the wire to the chip is and so on.
    So no, it usually is way way off.
    Also multimeter itself is a problem. Probe wire thickness, probe wire length, resistors of the circuit, general quality of the multimeter, calibration and so on.
    I have dirt cheap multimeter. (tt t-echni-c my62)
    Fluke ones are too expensive for me.
    Last edited by Overclocked; 12-19-2017 at 01:14 PM.

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    Default

    Quote Originally Posted by Overclocked View Post
    I'm sorry. I forgot to search it first...
    Thanks for sharing the topics.



    Also multimeter itself is a problem. Probe wire thickness, probe wire length, resistors of the circuit, general quality of the multimeter, calibration and so on.
    I have dirt cheap multimeter. (tt t-echni-c my62)
    Fluke ones are too expensive for me.
    Read the second link I provided before making assumptions.

    The accuracy, or lack thereof, of a DMM is nowhere close to that of a sensor half way across a motherboard PCB. And the accuracy of a DMM is properly documented with the DMM while the documentation of accuracy of a motherboard's sensing capability is completely missing.

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    Quote Originally Posted by jonnyGURU View Post
    Read the second link I provided before making assumptions.

    The accuracy, or lack thereof, of a DMM is nowhere close to that of a sensor half way across a motherboard PCB. And the accuracy of a DMM is properly documented with the DMM while the documentation of accuracy of a motherboard's sensing capability is completely missing.
    I looked the manual.

    For 20V DC measurement;
    Resolution: 10mV
    Accuracy: ± 0.5 % of rdg ± 1 digit
    ----------------------------------------

    For 2V DC measurement;
    Resolution: 1mV
    Accuracy: ± 0.5 % of rdg ± 1 digit

    It shows 1.6V for DC 1.5V LR6 AA battery. Hmm...

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    Default

    Quote Originally Posted by Overclocked View Post
    It shows 1.6V for DC 1.5V LR6 AA battery. Hmm...
    You understand that means the battery voltage is 1,6V, right?

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    Quote Originally Posted by -The_Mask- View Post
    You understand that means the battery voltage is 1,6V, right?


    I measured 3 different unused batteries. The result is the same. --> 1,6 V

    Used batteries have less voltage. That is why near-empty & used batteries can't power the circuits. Voltage is not enough for them.

    I also measured used batteries. Voltages are different.
    Used a little bit --> 1.5 V
    Much more used ones --> 1.06V , 0.8V , 0.45 V

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    There is another thread with the same question where I'd made some tests:
    http://www.jonnyguru.com/forums/showthread.php?t=15006
    The Software monitoring programs are far away to be accurate, for the PSU rails voltage monitoring.

    I measured 3 different unused batteries. The result is the same. --> 1,6 V

    Used batteries have less voltage. That is why near-empty & used batteries can't power the circuits. Voltage is not enough for them.

    I also measured used batteries. Voltages are different.
    Used a little bit --> 1.5 V
    Much more used ones --> 1.06V , 0.8V , 0.45 V
    You have at disposal a old style phone charger? If yes just measure the output voltage and then just look at the sticker on the charger for see whats the specified voltage. This shoud be better than measure a low voltage battery with a 3 digit multimeter.

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    Default

    It shows 1.6V for DC 1.5V LR6 AA battery. Hmm...
    Just because battery is specced at 1.5V, doesn't mean every single one will measure exactly that right out of the box.

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