Testing with a mutli...

Finally got myself a digital mutli for testing my rails (because MBM reads my +12 low so I need to see if it really is low).

Now I went looking online for which lines are which... but the same page also told me that I had to plug in a fan or something on the line I was testing and splice into the wires, so I was testing it with a current across it, otherwise i'd smoke my PSU.

I have a hard time beliving that, so i'm not going to trust what they say about the wire colors either.

Isn't it yellow + any black = 12v? Heck i'm not sure!

Black is ground, yellow is 12V and red is 5V.

I understand that black is ground... but why is there 2 of them? And what about 3.3v?

3.3 is the orange wire on your atx power, just ram the tester in there

PCGUY112887 said:

I understand that black is ground... but why is there 2 of them? And what about 3.3v?

Click to expand...

To carry more power and also to help isolate interference, a little bit. Some power supplys, including an older psu of mine had to have one of the wires tied to ground for the psu to turn on, don't just go searching for wires though, look it up on your psu manufacturers website, if it's not turning on. Also, cheap multimeters are notoriously inaccurate (mines a five dollar version ) so you might want to try it on a live battery to see how it compares, if the readings come up a little funny.