Is there a problem with the voltage on this one?

[coprocessor]

I have been asked by someone to get my PSU replaced as the 12V readings are LOW at idle speeds. Snaps attached:

Is there a need for doing the same? I'm a bit confused here.

Here's the topic:
http://techforumindia.com/index.php?topic=7596.msg40045;topicseen#new

I'm extremely sorry if posting third party forum links is not allowed. Admins/Mods can remove the link if required. Posted it just as a reference to the core issue and the resolution suggested.

Thanks !!

 

[lehtv]

One important bit of information missing: what is your power supply?

The deviation from the nominal value allowed by the ATX specification is 5%, 3% is considered tight regulation.

According to the values reported in the first picture (I think it's HWmonitor):

+12V: 4% regulation
+5V: 2% regulation
+3.3V: 5.2% regulation

I would rather trust your BIOS though. According to it, all the rails are regulated to about 1%. Everything seems to be fine.

Voltages don't stay constant, a higher load will have effect on regulation. But usually it only becomes a problem when stressing the power supply beyond its specified limits (for instance, higher than 500W load on a 500W rated power supply), often not even then.

 

[coprocessor]

One important bit of information missing: what is your power supply?

The deviation from the nominal value allowed by the ATX specification is 5%, 3% is considered tight regulation.

According to the values reported in the first picture (I think it's HWmonitor):

+12V: 4% regulation
+5V: 2% regulation
+3.3V: 5.2% regulation

I would rather trust your BIOS though. According to it, all the rails are regulated to about 1%. Everything seems to be fine.

Voltages don't stay constant, a higher load will have effect on regulation. But usually it only becomes a problem when stressing the power supply beyond its specified limits (for instance, higher than 500W load on a 500W rated power supply), often not even then.

Sorry about not posting those details. It's a Corsair CX600 PSU.

 

[postmortemIA]

One important bit of information missing: what is your power supply?

The deviation from the nominal value allowed by the ATX specification is 5%, 3% is considered tight regulation.

According to the values reported in the first picture (I think it's HWmonitor):

+12V: 4% regulation
+5V: 2% regulation
+3.3V: 5.2% regulation

I would rather trust your BIOS though. According to it, all the rails are regulated to about 1%. Everything seems to be fine.

Voltages don't stay constant, a higher load will have effect on regulation. But usually it only becomes a problem when stressing the power supply beyond its specified limits (for instance, higher than 500W load on a 500W rated power supply), often not even then.

computer is not much under load in BIOS - CPU and GPU are idle, so looking at voltages there might not help much.

 

[lehtv]

I'm aware of that. But I'm assuming the HWmonitor is also at idle, and I trust the BIOS readings more. OP asked whether there's something wrong with the voltages, and there's not. There's no reason to assume the voltages would not hold at full system load as well, the CX600 is a decent unit.

 

[fffblackmage]

Are you sure the software readings are accurate (BIOS or HWMonitor)? The one thing I trust for sure is my digital multimeter.

 

[coprocessor]

Are you sure the software readings are accurate (BIOS or HWMonitor)? The one thing I trust for sure is my digital multimeter.

Well, found an old multimeter lying around at my house. The black probe was not functioning. So, grabbed a cheap continuity tester and used it instead of the black wire/probe. Connected the red probe to the Yellow and the black one to the Black of a Molex connector on my box. Here are the readings:

I hope I've done the connections right here.

 

[coprocessor]

It seems there is some calibration issue on this one.. not sure. Here is the reading when I simply connect the two probes:

Considering this if I just subtract the difference from the original readings, it comes to 12.01V.

If required, I shall get a new multimeter. Kindly suggest.

 

[fffblackmage]

If you really want to get a new DMM and have a Harbor Freight Tools (HFT) nearby, HFT will often have a free DMM with a coupon and minimum purchase of $10. You can find the coupon in magazines like Popular Mechanics. It's a pretty cheap DMM, but it seems to work alright to me, as long as the battery isn't low.

If it makes you feel any better, I tested my PSU (Antec NeoHE 500W) at idle and at load using two different model DMMs.

(DMM1 / DMM2 / HWMonitor)

DMM1: that cheap HFT one
DMM2: old Micronta 22-188 from Radio Shack

Idle:
12.12V / 12.10V / 12.35V
5.01V / 4.99V / 4.95V

Load (Prime95 + Furmark):
12.08V / 12.08V / 12.29V
5.02V / 5.00V / 4.95V

The two DMMs don't seem to vary that much, but HWMonitor is a bit off, especially with the 12V.

 

[coprocessor]

If you really want to get a new DMM and have a Harbor Freight Tools (HFT) nearby, HFT will often have a free DMM with a coupon and minimum purchase of $10. You can find the coupon in magazines like Popular Mechanics. It's a pretty cheap DMM, but it seems to work alright to me, as long as the battery isn't low.

If it makes you feel any better, I tested my PSU (Antec NeoHE 500W) at idle and at load using two different model DMMs.

(DMM1 / DMM2 / HWMonitor)

DMM1: that cheap HFT one
DMM2: old Micronta 22-188 from Radio Shack

Idle:
12.12V / 12.10V / 12.35V
5.01V / 4.99V / 4.95V

Load (Prime95 + Furmark):
12.08V / 12.08V / 12.29V
5.02V / 5.00V / 4.95V

The two DMMs don't seem to vary that much, but HWMonitor is a bit off, especially with the 12V.

Helps a lot. I'm not in the States but can purchase it from a local dealer here. Just to be sure, was my calculation (deriving the voltage with the make shift meter) correct?

 

[fffblackmage]

Helps a lot. I'm not in the States but can purchase it from a local dealer here. Just to be sure, was my calculation (deriving the voltage with the make shift meter) correct?

It sounds logical, but I don't know for sure. I don't believe your PSU has any problems though. Like lehtv said, the CX600 is a decent unit, and you're not experiencing any problems and no component has died (well, so far).

Oh, try testing the 5V line. The resulting voltage after your calculation should be very close to 5V. If that's the case, then maybe your DMM just has a weird, but at least consistent, offset.

 

[coprocessor]

It sounds logical, but I don't know for sure. I don't believe your PSU has any problems though. Like lehtv said, the CX600 is a decent unit, and you're not experiencing any problems and no component has died (well, so far).

Oh, try testing the 5V line. The resulting voltage after your calculation should be very close to 5V. If that's the case, then maybe your DMM just has a weird, but at least consistent, offset.

Initial variance 1.18V.

Here's the 5V reading -> Red probe connected to the red connector (molex) and black to black (molex):

That makes it 5.05V. So things seem to be fine. Thanks again.

 

[fffblackmage]

No problem.

You know what, maybe the battery in that DMM is dying. Mine looks nearly identical and has a problem with readings like that when the battery is dying.

 

[coprocessor]

You know what, maybe the battery in that DMM is dying. Mine looks nearly identical and has a problem with readings like that when the battery is dying.

The battery was purchased just a few hours ago since the meter wont power on at all. I was told by a pal that there is some calibration issue with the device and it needs to be re-calibrated. Not sure how though.

 

[coprocessor]

Purchased a new DMM today.

Readings:
12.26V and 5.13V