Antec Power Supply -5 volts is -6.3 volts

[R]

I just installed a 460 watt power supply from Antec.
All voltages are very good except for the -5 volts which is -6.3 volts.
What damage can be caused with this voltage.
What hardware is the minus voltages used on.
What can be damaged with the wrong voltages.

Thanks in advance.

 

[Roger Hamlett]

I just installed a 460 watt power supply from Antec.
All voltages are very good except for the -5 volts which is -6.3 volts.
What damage can be caused with this voltage.
What hardware is the minus voltages used on.
What can be damaged with the wrong voltages.

Thanks in advance.

Forget it.
The reason for this rail being overvoltage, is that it generally now has
nothing at all attached, and on some PSU's, the regulator, cannot give the
right voltage without some small load.
Generally, the important rails, are the +3.3v, +5v, and to a slightly
lesser extent the +12v (most things using this rail, are devices like the
chopper regulator for the processor itself, and are more worried about
'stability' than absolute accuracy). The -12v, is generally only used for
the serial ports, and -5v, was used as a 'bias' voltage for the memories
fitted on the original PC's, and is rarely used now. Some sound cards
occassionally use it.

Best Wishes

 

[R]

Thank you Roger.

Forget it.
The reason for this rail being overvoltage, is that it generally now has
nothing at all attached, and on some PSU's, the regulator, cannot give the
right voltage without some small load.
Generally, the important rails, are the +3.3v, +5v, and to a slightly
lesser extent the +12v (most things using this rail, are devices like the
chopper regulator for the processor itself, and are more worried about
'stability' than absolute accuracy). The -12v, is generally only used for
the serial ports, and -5v, was used as a 'bias' voltage for the memories
fitted on the original PC's, and is rarely used now. Some sound cards
occassionally use it.

Best Wishes

 

[DaveW]

You need to return that PSU to the vendor for a replacement. The acceptable
error range for voltages on a PSU is 10%, before you risk burning out the
component that that PSU line is powering. 10% of 5.0 volts is just 0.5
volts difference. You're 26% out of spec.

DaveW

 

[Paul]

You need to return that PSU to the vendor for a replacement. The acceptable
error range for voltages on a PSU is 10%, before you risk burning out the
component that that PSU line is powering. 10% of 5.0 volts is just 0.5
volts difference. You're 26% out of spec.

DaveW

Does the supply actually have a -5V output ? Antec is switching
over to the newer ATX 2.0 standard for its supplies, and as
a rule those don't have -5V on them. Antec supplies usually
have a label on the side, and you can check the specs on there.

On the label of most power supplies, you will see "max" amps for
each output. Some supplies also list "min" amps, and if the
motherboard is not drawing that minimum current, the voltage
will rise and be out of spec. If the supply truly does have
a -5V output, and the label does list a "min" amp figure,
adding a resistor across the -5V and COM (ground) would
help to bring down the voltage. But that requires a bit
of knowledge of electronics to do safely. (Load resistors get
hot, and you need to mount them so they get some cooling air.
Wiring must be carefully insulated, so the wires don't touch
anything.)

Having a "min" amp requirement on +3.3V, +5V, or +12V is generally
not a problem, as those rails draw at least a bit of current.
The -5V is generally not used, and the -12V is used for the
serial ports (maybe 0.2amps or less). Thus, if you buy a supply
that lists a minimum requirement for those outputs, it will be
harder to achieve.

Knowing the model name and model number of the supply, and
any specs on it, would make it easier to advise further.
If the supply doesn't have a -5V output, for instance,
you can ignore whatever the monitor thinks it is seeing.

Also, what the monitor sees, should be verified with a multimeter.
The monitor hardware is only good enough to tell you something
isn't right, and a multimeter should be used as a double
check of the voltage.

Paul

 

[R]

Model: TP II 480
The power supply is 480 watts.
I would like to give my thanks to Roger and Paul for the accurate
information.
The power supply is the newer type.
They do not have a -5 volts.
Output
+3.3V +5V +12V1 +12V2 +5V SB -12V
First rule of thumb check all specs first then get the volt meter out.

 

[R]

One more thing you should go into the bios and disable the -5 volts in the
power section or
the computer will give you a message that there is a power problem.

Model: TP II 480
The power supply is 480 watts.
I would like to give my thanks to Roger and Paul for the accurate
information.
The power supply is the newer type.
They do not have a -5 volts.
Output
+3.3V +5V +12V1 +12V2 +5V SB -12V
First rule of thumb check all specs first then get the volt meter out.