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indygoraya

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TAKING A READING USING MULTIMETER

i WISH TO CHECK THE +5V DC supply on my pc,s motherbaord . Can you help me write down the sequence of steps that i would take, and the order  in which i would take tehm, to measure the supply. Using a digital multimeter with manual range selection. Thanks
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michko
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indygoraya

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Hi guys thats be really really helpful. Im going to be checky and ask . Supose if i was unable to measure any DC voltage in my PC and suspect that their is no mains supply to the PSU. What would be the sequence of steps that i would need to take in order to determine where the fault lays, while complying with saftey procedures. Thanks guys for your help
If you have no power coming from the wall to the PSU (if I'm understanding you correctly), then turn the dial on your Multi-meter to the appropriate ACV setting (120V for the states and 220V for most of Europe) and then use the leads very carefully in the wall outlet, and take the reading that way.

Of course, you can always just try another room or outlet.

If you mean that you have wall power but can just detect no voltage from the PSU to the motherboard,  then the easiest method is to try another PSU in the computer.  They change out very easily, and cost about $20 US.
I am quite sure there are many folks out there that know how to, and take the time to refurbish and repair PSU's.  For the minimal cost of these units now, it makes more sense to just replace them, in my humble opinion.
ok so what would be the sequence of steps to determine were the fualt lays as their is no mains supply to the PSU .  i have wall power but does not detect voltage.
The fault could certainly lie in the power cord going from the wall to the Power supply.  This can be easily tested by plugging the cord into the wall socket and then using your test leads on the end that would normally plug into the Power supply.  

Most likely, your power supply is faulty.  On systems where the Motherboard main power has failed, you still usually see some signs of life when the unit is turned on (an led on the board lights up, or a fan turns, etc.) even though there is not proper power to start up the system.  

If you still get nothing from the power supply, then I would recommend swapping in a new power supply.  If by some unreasonable misfortune, you change the power supply and still get nothing, then you will have to replace the motherboard.  From all indications (from what you've told us), it seems like you have a dead power supply unit on your hands.
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michko
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