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I have doubts on how to test VRMs on the motherboard.

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    I have doubts on how to test VRMs on the motherboard.

    I'm hoping to follow the guide on this link: https://www.badcaps.net/forum/showthread.php?t=600

    The OP contains the guide:

    Procedure for testing Voltage Regulator Modules (VRMs):
    (This assumes that any bad capacitor problems have already been fixed.)

    1. Turn off power to the computer.

    2. Remove CPU, memory, and all peripherals from motherboard. Disconnect power supply.

    3. This step verifies that the board is not damaged, and the VRM is not shorted:
    a. Measure resistance from power supply pin (+3.3, +5, +12, -5, -12) to input of VRM. Resistance should be zero (too low to measure).
    b. Measure resistance from output of VRM to load supply pin. Resistance should be zero (too low to measure).
    c. Measure resistance from input of VRM to ground (should be greater than 1 megohm, usually much greater).
    d. Measure resistance from output of VRM to ground (should be greater than 1 megohm, usually much greater).

    4. Install CPU, memory, and all peripherals to motherboard. Connect power supply.

    5. Turn on power to the computer.

    6. This step actually tests the VRM (all voltages taken with respect to circuit ground):
    a. Measure voltage at the power supply side of the power connector (+3.3, +5, +12, -5, -12).
    b. Measure voltage at the motherboard side of the power connector (+3.3, +5, +12, -5, -12). Anything less than the value obtained in step 6.a indicates a high resistance in the power supply connector.
    c. Measure voltage at the input to the VRM (+3.3, +5, +12, -5, -12). Anything less than the value obtained in step 6.b indicates a high resistance in the PC board traces to the VRM, and is probably not repairable, even with a schematic.
    d. Measure voltage at the output of the VRM. The value obtained depends on the functions being powered by the VRM, so knowledge of the expected value is required. Anything different than expected indicates a failed VRM (note that output may be higher or lower than expected if bad).
    e. Measure voltage at the device being powered. This requires knowledge of the device (which pins are power pins). Pinouts are readily available on the Internet for 30-pin, 72/144 pin, and 168 pin memory, as well as ISA, PCI, AGP, USB, etc. Pinouts for CPUs are either on the Internet or may be obtained from the manufacturer. Anything less than the value obtained in step 6.d indicates a high resistance in the PC board traces from the VRM, and is probably not repairable, even with a schematic.
    I'm unable to understand step 3, how can I measure resistance from power supply pin to VRM? With a multimeter, where would I insert the red probe and the black probe? Where do I find the input of the VRM?

    Is there a video which shows the above procedure being performed.

    I think these are essential details, which the author/authoress has deliberately left out.

    I'm facing constant game crashes, so far I have replaced the mb, gpu, ram and psu, Even after doing all these, the problem hasn't gone away. I downgraded to Windows 7, driver, chipsets, etc and they haven't resolved the problem.

    I think the motherboard is faulty and it is not supplying enough voltage which is causing the games to crash. How can I check the VRMs?

    #2
    Re: I have doubts on how to test VRMs on the motherboard.

    Google "ATX connector pinout". The measurements you would make are between one of the pins carrying the voltage in question on the ATX connector (doesnt matter which, they're all tied to the same rail for the same voltage), and the output of the VRM (e.g. after the coil).

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      #3
      Re: I have doubts on how to test VRMs on the motherboard.

      @gaming
      That guide is very old from around 2005 - it may not apply so much to your motherboard

      If your PC is powering up then generally I think it is fair to say the VRMs are working. If you want to know the voltage output from the VRMs (Vcore, and maybe VTT) then you can measure this using a voltmeter from one or more of the inductors near the VRMs around the CPU socket. Positive meter lead to iinductor and negative to ground

      What Motherboard and CPU do you have?
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