Motherboard Install Problem

[mhubbard]

I am installing a mobo to replace a dead one. After installing it would not boot at all, in fact, no power as no fans were spinning. I plugged a new ps into the mobo, same result. I checked my cables for the power and reset switch. Then, tried again, pc went into BIOS. Plugged the original ps back in and BIOS came up. I thought all was well. I went ahead and plugged in the rest of the front panel connectors, speaker, hdd led, etc. and pc came up fine. I powered it off, installed the rest of the devices, and now no power again. I unhooked everything but the mobo and still no power. I disconnected and connected the new one again, pc came up. I connected the old one back, pc came up fine. Went to the bathroom, and pc would not power again..... and I made no changes....weird. Bad mobo or a short somewhere??? How do I check this????

Thanks!!

After further review, I had purchased 2 of these mobo's so I decided to try the other one for fun. Same darn thing. Intermittent.... So now I just think maybe it is a PS issue. One of the PS is a 350 and the other is a 250. Maybe neither are compatible with the ne sempron's?????

[arch0nmyc0n]

I'd agree with you that it could be the power supply. Do you have a voltmeter to check it out? or perhaps one of those nifty power supply checking devices specifically made to test them?

[mhubbard]

I went out and bought a brand new 400 watt ps to either fix it or rule this out as a problem. Same problem.... It is intermittent, sometimes it will power up like normal, sometimes won't get any power at all, no fans spin or anything. I am stumped....

[Budd]

and the mobo is still in the case? maybe pulling the board and set on the antistatic bag it came in a try booting up outside of the case. that'll rule out a short

[mhubbard]

Yeah did that too. I pulled it out and same thing. I waited a few minutes...then it started to work. I tested several times and worked well. Then all of a sudden it stopped. Funny thing is I have 2 of these brand new mobos and they both are doing this.... So that almost rules out a mobo problem.....almost....

I have checked everything.... made sure it wasnt shorting out and touching the metal on the case, clear cmos jumper is not jumpered...tried 2 sticks of memory to rule memory out. I appreciate any help......

The only thing I can think of that could be an issue is maybe the power switch cable(for the front power switch) that plugs into the mobo is bad...I may pop one of these in a different case tomorrow for poops and grins....

[mhubbard]

I think I may have figured it out. I got the scond mobo out to make sure I didnt miss anything....well I forgot to check the clear cmos jumper on this mobo so I fixed that and it works perfectly now. So I turned my focus to the 1st mobo. I plugged it in to bench test and it worked ok. I tested a few more times ok. Then it powered off when I inadvertantly nudged the power switch leads on the mobo. I jiggled them and the system would power on and off at random. That looks like my culprit.....

Thanks for all the help...

[arch0nmyc0n]

and the mobo is still in the case? maybe pulling the board and set on the antistatic bag it came in a try booting up outside of the case. that'll rule out a short

Out of curiousity, and I'm no expert on materials, but wouldn't an antistatic bag be considered a conductor as I assume it absorbs static charges?

[mhubbard]

Thats what I thought too..... I always just sit them on the box they came in.... I have read that cardboard is the best for bench testing.

[arch0nmyc0n]

yeah, I'd also assume that antistatic bags have a lower melting threshold than cardboard. Again I'm no expert, but I'll stick with the cardboard...

[bookmarkmns]

For Mobo testing I use a trials rig. ATX and BTX boards. Came across a guy who designs them. Excellent KIT! I'll post details if requested.

[arch0nmyc0n]

you got a bookmark there bookmark? any website I can check them out on?