0

My PC won't boot anymore (not even POST beeps).
I measured the power supply. All voltages are PERFECT except the negative rail. My multi-meter shows -11.2V instead of -12V.

Is this rail necessary for the PC to pass the POST test?
From what I understand the negative rail is only for backward compatibility only....

The power supply is 750W (from Antec). Worked for 11 years.

Improve this question
5
  • 1
    I think the -12V supply only needs to be within +/-10% so 11.2 is fine. The others are +/-5%
    – Finbarr
    Commented Dec 22, 2022 at 16:12
  • 4
    Good chance your PC doesn't even use -12v.
    – user1850479
    Commented Dec 22, 2022 at 16:13
  • Yeah, the only thing I know for sure might use -12V is RS232 but many RS232 transceivers generate the required voltages themselves these days to avoid unnecessary power supplies. Vaguely related: Why is -12V needed on an ATX power supply and The purpose of PSU & motherboard -12V line
    – Mokubai ♦
    Commented Dec 22, 2022 at 19:30
  • "I measured the power supply" -- How? With or without a load?
    – sawdust
    Commented Dec 22, 2022 at 22:01
  • @sawdust - with mainboard connected and powered on.
    – IceCold
    Commented Dec 27, 2022 at 18:15

0

Reset to default

You must log in to answer this question.

Browse other questions tagged .