Possibly a dead PSU?

[flyingpotato]

Hey guys, i've recently been having some issues with my pc, so I dug out the monitoring software to make sure it wasn't anything for overheating. (HWMonitor),and I noticed in the reported voltages, the -12v seems to be much lower than the +/-10% i've been told to allow for software.

May this be an indication of a defected psu?

 

[lehtv]

What is the power supply?

As far as I know, -12V is normally not used by modern motherboards. +12V is the main voltage, +3.3V and +5V are the secondary voltages.

Also, software readings are not entirely reliable. The only way to properly measure voltages is with a multimeter connected directly to the power supply's wires

 

[flyingpotato]

The psu installed right now is: http://www.newegg.ca/Product/Product...82E16817341010

How 'modern' is modern in this case? the PC is relatively old. (3 years?)

I don't really have a multimeter to hand until after Christmas.

 

[lehtv]

Did some quick googling and it seems -12V is needed only for RS-232 serial port devices which almost no one uses these days. Some low end motherboards still have them for legacy compatibility.

If you're not seeing any actual instability or other symptoms that might be PSU related, don't worry about it.

 

[flyingpotato]

Defiantly no Rs232's on my pc.

Thanks for looking into this for me lehtv!

 

[lehtv]

No problem ! 🙂

 

[bryanl]

Did some quick googling and it seems -12V is needed only for RS-232 serial port devices which almost no one uses these days.

RS-232 needs -12 but not necessarily directly from the ATX power supply because all but the very oldest motherboards use TTL/RS-232 interface chips that generate +12V and -12V from +5V or +3.3V. This applies even to most motherboards from the late 1990s.