Thread: Diagnosis MotherBoard OR PSU?

I dont understand what you are saying...

You mean when you press the button, the mobo fans turn on, but probing the 5v and 12v rails with a multimeter you get 0v readings? That should be impossible since the mobo fans are running.

And "refuses to turn off", do you mean the fans? Do you get POST errors? Do you get it to POST?

I can't tell from your broken-logic post what is going on, what you have done, or what you expect it to do...

I'm sorry the devices on the 5 and 12 rail don't have power and by turning it on I mean using a key to connect the connectors on the MB

I dont even get a video signal from the board

Originally Posted by yam125

I'm sorry the devices on the 5 and 12 rail don't have power and by turning it on I mean using a key to connect the connectors on the MB

I dont even get a video signal from the board

Well that sounds like a memory or cpu problem to me. Since yours is integrated I would say RAM.

Easy way to tell is break out the multimeter and probe the power connectors.

Devices not turning on means diddly. Some (most of the new ones actually) require a command from the MB before they initialize to save power.

Power connectors to what? Ram?

You can't probe the RAM power connectors, they are in the DIMM socket...

But you want to test things. So your standard molex connector has 2 grounds, a 5v lead, and a 12v lead. Probe between 5v and ground and then 12v and ground. If those are ok, I would assume the whole PSU is good. But to be thorough, you could jumper hack the ATX cable and probe all voltages including the 3.3v and such just to be sure.

My money is on RAM. Wrong type, speed, size, or density.

The ram is in spec for the board i've been using it and then all of a suddon it pooped out.


I wantedto find a somebody witha psu tester but I haven't been able to. I have to look up how to do the jumper bc I can't probe on this psu while it is connected

Originally Posted by yam125

No if been using it and all of a suddon it pooped out.

well that is another useful tidbit you neglected to mention. If you want help, you need to lay out the details instead of us trying to do it 20 questions style...

Probe your PSU with a jumpered ATX cable, and see what the voltages are at.

When you probe it, it should be disconnected.

Jumper pin 14 (the turn on), to ground (any of them), and the PSU should turn on.

In addition, some details as to the specs of your system might help determine the problem.
Include the HDD formfactor and any/all USB devices connected.

It's very possible that there is more power draw than the M3 can provide.