PC Help - No Power

[mrsimperless]

So I get home from overseas and one of the first things I notice is that my pc won't turn on. I ask my brother about it and he says that it happened the morning of the day I got home. He said he woke up and noticed that his alarm clock was blinking as he was late for work so that we had a surge or an outage.

I got around to troubleshooting things today and took the power supply out and tested it. No problems, it turns on just fine and powers a case fan. I plug everything back in and nothing again. My next suspicion is the motherboard, but I have no clue how to test anything beyond this point. Anybody out there more experienced in these kinds of problems?

[mrsimperless]

I've removed all pci and isa cards and still nothing. I also ruled out the switch by shorting out the pins it connects to and no luck. I might try memore next, but after that I may be out of options.

[Peregrine]

Memory is definitely an option - if you try to turn on the PC, what happens? Just nothing? Do you hear any beeps? Usually if it is a processor or memory failure the system will invoke a beep code to give you some idea of the issue. If not, your motherboard could be shot - good idea in removing the cards, I usually strip the computer down to just the graphics card (if you have one) and go from there.

[MizzouRah]

Any lights on your MB?

[Greyroofoo]

Funny, I just had my power supply go out on my own computer. Luckily I had one in an old computer though.

[mrsimperless]

Everything is completely dead. I get no lights, no beeps, nothing at all. And I'm sure that it is not the power supply. I'm going to try memory next I think, but I have a bad feeling about the mobo...

[Peregrine]

If you have more than one memory chip, try removing one and starting the computer with just one, then the other. If that doesn't work, looks like your mobo is most likely done for.

[PilotMan]

well, if we ruled out the power supply and nothing else happens then I would think that the mobo is the next culprit. Especially if you are seeing no post test or bios at all. Honestly, at this point changing out the mobo isn't that big of a deal, especially if you have already taken it apart most of the way.

[MizzouRah]

Yeah.. I would suspect mb as well. Take all the memory out and then try to power it on, you should get beeps.

Processors going bad are extremely rare. *unless* someone puts a pc together and they don't have the heatsink/fan installed properly. :)

[mrsimperless]

Tested with each memory stick alone in the 1st slot and then with no memory whatsoever and the result was the same. Final test was every single peripheral and component removed except for the mobo and processor along with a case fan for load and still the same result. Just completely dead.

I'm thinking of going out and getting a multimeter tomorrow or early this week as I need one for a car project anyway and testing some of the voltages on the psu wire harness to the mobo. If those check out then I will definitely be looking at getting a new mobo from NewEgg.

The problem is that this is an HP "Media PC" (HP Media Center PC m7680n - don't ask, I was feeling lazy and it was on sale the week before Vista came out) and I'm not sure how standard the motherboard is. I tried to get rid of the Windows Media Center Edition it came with and put in XP soon after I got it, but all efforts were met with blue screens and other errors, so I gave up and left it alone. I haven't put together a rig or done much reading up on hardware since the P II/celeron/classic AGP days, so I've got a bit of research in front of me. I'm even considering buying a case when I get the new mobo and just pilfering this thing for parts. It has a TV card in it that would be perfect for the linux DVR box I'm looking to build for my parents.