Should I have -8.9 volts on a -5 volt rail

[Linus No Beard]

i don't have a DC multi meter so i am using CPUID HWmoniter and my voltages are as such

+3.3V is 2.028

+5V is 3.347

+12V is 8.064

-12V is -8.064

-5V is -8.928

+5 VCCH is 2.843

VBAT is 1.548

 

Is my PSU bad or is that normal my BIOS conforms these number to be true it only shows me +5 and +12 in bios but they are similar so i trust what HWmoniter says

[WhitetailAni]

Your 12V rail is 8V?
Uhh... That's bad.

 

What PSU do you have? I haven't seen many modern PSUs that still have the -5V rail...

[Linus No Beard]

1 minute ago, FakeKGB said:

Your 12V rail is 8V?
Uhh... That's bad.

 

What PSU do you have? I haven't seen many modern PSUs that still have the -5V rail...

a corsair vengeance 650 watt it is 1 and 1/2 years old also front USB 3 does not work on my case but i still have the cable pugged in should i remove that just to make shore that is not where the short might be

[aDoomGuy]

Software monitoring isn't reliable.

[Linus No Beard]

1 minute ago, aDoomGuy said:

Software monitoring isn't reliable.

well it is the best i got even if i had a DC multi meter i dont feel safe sticking probes in random places hoping i dont short something

[tikker]

9 minutes ago, Linus No Beard said:

well it is the best i got even if i had a DC multi meter i dont feel safe sticking probes in random places hoping i dont short something

That's why you don't stick probes in random places, but check the data sheet or some other reference what to probe...

 

17 minutes ago, Linus No Beard said:

so i trust what HWmoniter says

I do not. If your 12 V rail was really only capable of delivering 8 V then 1) the PSU is a goner and 2) I don't think the PC would even turn on. On the chance that you are in fact getting these wacky voltages I'd say get a multimeter to check or stop using it immediately and get a new one.

[Dedayog]

7 minutes ago, Linus No Beard said:

well it is the best i got even if i had a DC multi meter i dont feel safe sticking probes in random places hoping i dont short something

When he says software monitoring isn't reliable, it means ignore those results.  Meaning... there isn't anything wrong most likely.

 

You're chasing ghosts.  Unless there is something going on that made you check the HWInfo in the first place, but you haven't said?

[seon123]

7 minutes ago, Linus No Beard said:

well it is the best i got even if i had a DC multi meter i dont feel safe sticking probes in random places hoping i dont short something

 

16 minutes ago, Linus No Beard said:

but they are similar so i trust what HWmoniter says

Both use the same, equally useless sensors. It doesn't matter if they're the best you've got, what matters is that they're useless. If you want more random numbers that are completely irrelevant, I suggest getting them from random.org.

https://www.random.org/

[mariushm]

The measurements are not accurate. In fact they're most likely completely bogus.

For one, unless your power supply is 15+ years old, it does not produce -5v - this voltage is deprecated and power supplies are allowed to no longer have this voltage or even have the wire in the 24pin connector.

It was used in ISA slots if my memory is correct, before pci-e, before agp. before pci.

So your bios makes something up, and lists approx. -9v when there's nothing there.

 

-12v does exist in power supplies, but it's strictly used by the serial port, which may not even be there as a connector on the motherboard, it may only be as a header. It's not used.

Because it has only this obsolete function, most power supplies don't even bother to regulate it properly and with nothing using this -12v, it's quite common to see even in high end power supplies something like -10v instead of -12v.  All serial devices are actually designed to treat anything higher (more negative I mean) than around -8v as a digital 1 and anything else as a digital 0, so accuracy doesn't matter.

 

What should be obvious to you is that it's extremely unlikely that your power supply outputs exactly 8.064v on 12v, and exactly -8.064 on -12v ... exactly the same number to the millivolt.

 

The battery is a lithium one, and will be basically fully discharged at around 2v...You'd probably get bios warning messages saying settings can't be kept when the battery goes below around 2.7v ..so VBAT is also obviously an incorrect value.

 

If you have mechanical drives, your drives would not start with 8v ... so again, stupid software.

 

Try other software, maybe Aida64 or hwInfo but the easiest and most accurate would be to buy a multimeter - even a 5-10$ one is accurate enough to be useful, and usually more accurate than software.

[Linus No Beard]

3 minutes ago, mariushm said:

Try other software, maybe Aida64 or hwInfo but the easiest and most accurate would be to buy a multimeter - even a 5-10$ one is accurate enough to be useful, and usually more accurate than software.

ok but butting metal in a on pc does not sound smart also that does not solve the problem the + Voltages being off

[mariushm]

The multimeter has probes. You simply put the multimeter on DC voltage and you put the probes on the outputs of the power supply.

A convenient connector is the old molex (hard drive) connectors which have +5v and +12v so you could simply put the probes in the connector and get a voltage reading :

 

3.3v is a bunch of wires in the 24 pin connector. You can google "atx 24 pin connector pinout" and you get the connector layout.

 

Here's a video showing how to check a power supply using a multimeter:

 

 

 

 

 

[LWM723]

Spend $5 on a multimeter!

[tikker]

1 hour ago, Linus No Beard said:

also that does not solve the problem the + Voltages being off

The problem is the software not reading the voltages correctly. As you don't mention anything about your PC malfunctioning, voltages are probably fine. If you want to know for sure you go the multimeter route and measure it yourself.

[Linus No Beard]

8 minutes ago, tikker said:

The problem is the software not reading the voltages correctly. As you don't mention anything about your PC malfunctioning, voltages are probably fine. If you want to know for sure you go the multimeter route and measure it yourself.

ok

[aDoomGuy]

I've seen voltages of 100 000 volts in my computers lol. I wouldn't get alarmed until there clearly is something wrong with the PC.