LinuxQuestions.org - Crap. I think I blew a fuse first time running my new barebones ubuntu box.

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Sorry too much alcohol ;) That should read "1 ram module, pc speaker, on/off switch and graphic card."

That's the case speaker, not speakers through sound card. That way you can hear any beeps.

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There is power going to the board. I connected it again and a green LED on the motherboard turns on when I flip on the power. However, the optical drive, when connected, won't run anymore and neither does the harddrive seem to move anymore. (I tried all this stuff before I read your post).

12 volt line is down. Check if you have +12 out of the PS before doing anything about the mobo.

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Originally Posted by jiml8 (Post 3067697)

Check if you have +12 out of the PS before doing anything about the mobo.

Yes. You (djzanni) mentioned before that you used the fans turning on as confirmation that the power supply was good. This is not necessarily all you have to check. Since you now have a voltmeter, you should check to see that the voltages are what they should be (as I described in my other post). In particular, check the 20-pin connector first, and then check all the 4-pin connectors. If you have SATA power connectors, they will not be so easy to test (the pins are small), but if all the rest work, then you can be pretty confident that the SATA power cables work as well.

IIRC (but don’t hold me to it), the hard drive should spin even if it isn’t connected to the motherboard (i.e., a non-spinning hard drive indicates a faulty power supply, not a faulty motherboard).

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IIRC (but don’t hold me to it), the hard drive should spin even if it isn’t connected to the motherboard (i.e., a non-spinning hard drive indicates a faulty power supply, not a faulty motherboard).

Depends on the drive, and on how its options are set. Drive could be spun down until commanded to spin up, which the controller will always do on startup.

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Originally Posted by osor (Post 3067712)

Oh right. I didn't do this the first time because I was warned against having the power on too long. But I guess what I'll do is put the voltmeter in first, short the pin and then plug the thing in to read what the voltmeter says. That should work. I may have to get my wife to help me with a couple extra hands.

~daveZ

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Originally Posted by osor (Post 3067548)

How did you test it? This is how you generally test an ATX power supply:

Take the power supply out of the computer.
Turn the rocker switch off, switch the power supply to the 115V setting, plug in the power supply (to mains), turn the rocker switch on.
On the large 20-pin connector, short pins 14 and 15 (e.g., with a paper clip). The power supply should now be on (if it has any internal fans, they should turn on).
Use a voltmeter to check the DC voltage with respect to ground (any black wire) of the 3.3V rails (orange), the 5V rails (red), the 12V rails (yellow).
You should do this with the various four-pin power connectors as well (the ones you use to power drives and such). They will not have orange wires.

You should probably look at a pinout to be sure which pins you need to short. The pinout will also show you the colors (and voltages) of the other pins, so you won’t have to strain too hard. On the four-pin molex connectors, the wire colors are easy to see.

This test of course only makes sure the voltage readings are correct, and in particular, it does not test the performance under load. The only way to do that is to use a good BIOS which has a PC-Health Status section (which you should try after you verify that the voltages are sane). Obviously, if you cannot even get the motherboard to POST, you will have fried something on the motherboard.

OK Osor, I did all the testing above as you described and all the voltages check out. So I think the power supply is probably intact, but of course as you say I'm not going to know for sure without a working motherboard. Thanks for the help. ~daveZ

Yep. I got a new motherboard and everything works great now. Thanks to everyone for your help.

Despite the frustration, it was actually a little bit of fun troubleshooting. I'm not a hardware person so it was good fun to actually make use of a voltmeter for pretty much the first time.