Missing Voltage Rail in PSU?

[sbab123]

Hi all,

I was checking my PSU voltages with the CPUID HWMonitor: http://

Below is the screenshot:

Can anybody please tell me where are:

+5Vsb
-12V

These 2 voltage rails are missing!

Is there a problem with my PSU or motherboard?

Please let me know, because these 2 voltage rails should have been present

Regards

 

[sbab123]

Somebody, please help me...

 

[Eximo]

You do realize that the power supply doesn't offer any sensing of its voltages at all (excepting those few fancy all digital supplies). All of that information is coming from the devices running on that power? If they chose not to detect those voltages, then you won't seem them.

-12 is not typically used in contemporary computers. It is kept in the ATX standard to support older and legacy hardware that does.

5V Standby is used only to trigger the system's start, it is generally supplied from the same 5V power circuit as the operating 5V.

 

[Zerk2012]

I see all your voltages.
12 volt.
3.3 volt.
5 volt.
-12 volt is not a voltage, negative/ground depending on the term you wish to use.

 

[Eximo]

With respect to ground -12 is totally a voltage you can get out of the bridge rectifier, so 12- -12 can get you 24 volts out of an ATX supply. Serial RS-232 used to use 12 and -12 for its communication, but since that is almost completely extinct you may see -12 drop off the standard, much as -5V did (which was apparently is something ISA slots needed)

 

[Eximo]

In a lot of modern power supplies the 5V is actually provided by a DC-DC converter running off the 12V output.

Rails themselves aren't distinct power circuits, all the 12V is coming from the same place. What it really means is how much current is flowing through a sensor. If it is exceeded the supply will shut off. Thus when you have a multi-rail supply you have to balance the load. Usually the wiring will force it on you anyway. CPU/Motherboard usually get a rail, and the PCIe will be on another.