electrical difficulty

[fpoverflow]

Thought I had cured my problems setting up my system. Here are the gory details..

previous post

Basically I pulled my motherboard out of the case and onto my table, and moved my RAM to another slot, and all was well at last.

I slowly put the system back together inside the case. I periodically turned the system on to make sure all was well. I added CD drives, wireless network card, hard drives and cables. But when I got to the end and everything was hooked up, of course the system would not boot once again. No beeping, no nothing except for spinning fans. The link above has more detail.

So, I pulled out all the IDE and floppy cables and power, just to make sure I don't have something hooked up wrong. I remove the wireless network card as well. I power the system and it boots. I put the wireless card back in, no boot. I take it back out (I'm suspicious) and the system doesn't boot.

Now I have stripped the system down to the basics in the case -- RAM, video, CPU and fans. And it does not boot, just as before.

I'm thinking I might some sort of electrical short, but I'm not very experienced with that sort of problem. How could I determine if this is the problem?

I have basically every screw in the motherboard screwed to a post coming off the case. I didn't use any plastic risers, because I figured the metal posts would be better. Should I attach the motherboard in a different fashion?

Thanks for your help, this problem is very frustrating.

 

[AgaBoogaBoo]

Maybe you need a new PSU?

 

[fpoverflow]

I don't think the PSU is defective since it has always provided power. The fans always spin, and the LEDs on the MB always light up. It is an Antec True 430 that was an upgrade for my Antec 3700 case. I didn't install the PSU into the case, directron did. Is it possible they installed it improperly and that it is causing these weird problems? Problem is, I don't know where to begin in terms of electrical problems in a computer.

But it does seem that when the motherboard is seated in the case, that the motherboard posts erratically if I start adding or removing components. It seems to be very sensitive to movement.

As I said, I added a card and the system stopped booting. I took the card out, the system booted. Then I put the card back in, the system boots. Remove the card, system stops booting. Since there is not pattern to when it will boot, it seems it has to be related to movement of the mb. Also, adding and removing screws which secure the mb has changed its behavior as well.

Help!!

 

[DaTT]

Although you say all these changes changed the behaviour of your system boots, I suspect that it is mere coincidence. You said in your last post that you originally had your RAM in socket 3? What socket is it in now? It should be in socket 1 if your only using 1 stick. Make sure that it is seated properly (both clips snapped shut).

Check mobo for any leacking capacitors (yellow or brown sh|t either on top of cap or on mobo near bottome of cap). Ensure all power cables to the mobo are "clicked" in and seated properly.

Reset your BIOS

 

[fpoverflow]

Ok. I'll try that. I have reseated the RAM a few times, since that seemed to fix the problem the first time. I tried both slot 1 and 2. The clips are definitely snapping, but like I said I'll try it again because reseating can sometimes help.

I'll also reset the bios using the 'insert' key trick and see if that helps. I'll let you guys know how it goes.

 

[DaTT]

reset the BIOS with either the jumper on the mobo, or remove the battery for like 20 minutes. No tricks

 

[kursplat]

also check out your fans if you think it's just electrical. unplug them (careful if you do the CPU fan) and replug them one at a time . check the system each time . i had a baycooler die once that crashed the whole comp when it was pluged in.
good luck

 

[fpoverflow]

Damn. Reseated the memory through all the available slots. Checked all the capacitors, and reset the bios using the mb jumper. Also checked the power connections to the mb from psu. It's still doing nothing.

I also took out the RAM completely and I got no beeps, which says to me that the problem is happening very early on in the startup process, before even the presence of memory is being tested.

 

[fpoverflow]

You are not going to believe this. Just to test out my theory I did the following-- I took the motherboard out of the case, and placed it on a cardboard box. I did not disconnect anything. I left everything connected exactly as it was when it was in the case. I hit the power button on my case-- bang, it boots.

So it almost definitely seems the problem is related to the case/mb interaction. I have an antec 3700amb, and there about ten post screws on the case. When I put the mb in, I screw all these in so the mb is fastened very securely. What can I possibly do to fix this problem?

 

[fpoverflow]

Last update for tonight. While mb was out of case, I noticed there was one standoff screw installed in the case that I was not using. I was actually pretty close to being below the cpu socket, and must have been inserted at the factory. I immediately took that standoff out. Put the mb back into the case and screwed it in. It is working again. Question is, will it continue working or fail again like last time? Does that extra standoff seem like a plausible cause?

 

[Burninator]

is the computer your using now the computer thats fuxed up?

 

[fpoverflow]

No. Family Dell computer.. I got them a Dell so I wouldn't have to bother setting it up. Oh, the irony.

The computer that is fuxed up is sitting on my kitchen table in about 20 pieces, although it is currently getting to the bios screen

 

[emjem]

Yep, an unused misplaced metal standoff can short out the mobo. Sounds like you fixed the problem. And your lucky that the mobo wasn't damaged by the short.

 

[redhatlinux]

Your posts describes a 'bogus' standoff exactly. When you installed the NIC card you flexed the mobo a bit, and the standoff shorted out the mobo. Same thing when you installed the ram, little pressure mobo flexes and no post. Once this has happened to you just once, you will always double check that the standoffs match with the soldered rings on the mobo holes and that you don't have any extras.

 

[DaTT]

Keep us posted on this. And keep trying to to make sure it works. This is definitely something that would have to be fixed by actually seeing it. I personally would have never thought of that unless I actually saw the setup in person. Hope it works now.

 

[tweeve2002]

i know one kid who fried a motherboard, he had a screw under the the board and didnt see it when he replaced the board. This happend in my computer Tech class at my high school. boy was the teacher Pissed

 

[fpoverflow]

I'm happy to say that the system has been completely stable since removing the bogus standoff. I didn't notice it earlier on because it was always covered by the cables coming out of my PSU, before I would place the motherboard in the case. I guess it is really important to pay close attention when putting together a system. Thanks again everyone for the suggestions. Without all the feedback I think I might have thrown in the towel long before I found the culprit.