Power Supply Voltages

[thehahaguy]

Ok I just recently bought a Corsair TX750w power supply. I check the voltages in Speedfan (not sure what else to use) and all of the voltages seem fine but the -5v is at 4.05v. Now I dont even know what -5v is even used for so I am not sure if I need to worry about this or not. Is it ok where it is running or don't it matter. I do know a good amount about computers but I just never knew what -5v is for and what it should be. If some could shed some light on this that would be helpful. Also the -12v is at 0.64v, should I need to worry about that too?

I am not sure if I am posting this in the right area or not. Sorry if I should have posted somewhere else.

[slaveofconvention]

If your PC is running ok, I wouldn't worry about it - I had a similar problem recently and ended up taking a multimeter to the thing to try to figure out what was going on - the readings you get from speedfan or any software monitor aren't always correct...

As for the -5v, I think that's something which USED to be important but isn't really used anymore.....

[thehahaguy]

Ok thats what I thought about the -5v thing

Here is what SpeedFan is saying my voltages are.

[Diamon]

The voltages will always be incorrect where measured like that. You need to plug something into the 5-volt rail and then measure it with a multimeter.

As for what it's used for I'd say mainly fans and LEDs. Not sure if the mobo uses 5 volt at any point though.

[thehahaguy]

Ok now its like not working. =/ Those voltages looked fine the last time I checked them but last night after my first post my computer went to sleep but not all the way. My fans where still running, my keyboard was still on and the power light was not blinking and it should be but the monitor turned off. So I took out the new psu and put it into a computer build I did a few years ago and when I turned in on you could hear constant clicking, well I shut it off right away because I didn't want it blowing up or something and installed the old one that was in that computer and it fired right up. No clicking no nothing, just worked perfectly. Could it be I got a bad PSU or is it just that all the computers im installing it in are too old? But that shouldn't matter should it?

I do not have a power supply tester or a multimeter at hand right now but I can borrow if I need too.

[Diamon]

If it is making weird noises or generally freaking you out you should contact the store where you bought it.

This applies to almost everything you buy that uses electricity

[Konrad]

-5V is only used by pre-PnP ISA/EISA/MCA cards, modems, and RS232 implementations that are all ancient and long obsolete. No, beyond obsolete, more like extinct. Legacy-free systems don't even bother to use -5V, the pin isn't even present on many ATX PSUs and MBBs. There might be a few leftover UPS devices or server peripherals which make use of -5V.

Realistically, the only reason you'd ever need -5V these days is when connecting homebrew hardware designed to fiddle with quirks in ATX standard voltage requirements, something like a 17V fan for example, though the PSU isn't engineered to be abused this way so best of luck and kiss your warranty goodbye if you want to try it.

[thehahaguy]

ok thanks for the help