Question Voltage question

Aug 4, 2020
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Hey all; I just started a build for a neighbor today; after I got everything plugged in, I fired it up. The CPU fan ran intermittently, the front case fans not at all, and the rear case fan ran fine. I pulled the power supply to test it, and ran in to something I haven’t before.
The PsU is a power spec 650w Bronze.

my yellow 12v are reading 14.86
My orange 3.3 are reading 4.13
My red 5v is reading 6.54
My blue -12v is reading -14.16
My purple 5v is reading 6.25

I have never run into this....... I’ve only ever testing PsU’s and found them nominal or dead..... not putting out extra voltage; I also have no idea whether this is bad; my gut says it’s bad.... but maybe I’m wrong.
Ideas?
Thanks in advance!

banjo
 

DSzymborski

Champion
Moderator
It happens sometimes if the PSU is defective. I assume you're reading this with equipment and not something like software?

The more recent Power Specs are better. This one is pretty bad, an old group-regulated Sirfa, but there's likely also an internal issue causing these problems.
 
Aug 4, 2020
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Yes; I tested it with a Multimeter. Thanks for the quick response. I took a gamble on it since my neighbor is on a tight budget, this isn’t the first powerless Ive had that has been defective unfortunately! Thank you again!
 
Aug 3, 2020
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Make sure your meter is calibrated and that there is load on the power supply - some PSUs will not function properly without load.

If those two are ticked then definitely replace your powersupply. Take it in for a refund if you purchased it recently.
The ATX specifcations states voltages must be within =-5% of the nominal. Those readings are far out.
 
Aug 4, 2020
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Make sure your meter is calibrated and that there is load on the power supply - some PSUs will not function properly without load.

If those two are ticked then definitely replace your powersupply. Take it in for a refund if you purchased it recently.
The ATX specifcations states voltages must be within =-5% of the nominal. Those readings are far out.
You nailed it; I checked my multimeter and it was not correct. Borrowed a neighbors, and the psu was in the right ranges.......

Thank you; what a bonehead move on my part; got so tunnel visioned I didn’t even think about that!
 

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