Some seriously concerning problems :(

Alright, I consider myself knowledgible in the ways of building computers, but it seems that ever time I build one, some insanely uncommon problem happens and after a month of troubleshooting I fix it and move on with no other problems. Well guess what, I built a new computer.

AMD x2 3800+ on the abit fatality an8 sli board with 6600gt on the pcie with nothing special 1gig ram and some drives.

Runs great, get xp pro on there, but start getting some disturbing BSOD's that seem to be random. They talk about making sure bios does not have cacheing, sometimes dont give a filename, sometimes name win<somthing>k.sys with "page file in non paged area" errors and physical memory dumps. Which means I have some hardware issues. The 80gb HD I have as the master is old, but not old enough to have sectors bad enough for these BSODs. So the next time I had the BSOD I open the machine to blow out slots and make sure everything is seated properly.

Upon taking it off the work bench I set it on the floor a bit too hard (this is when the fun started). When working on the machine I switched the ram in their slots, to start to rule out bad ram/slots and gave everything a good check for connectivity. Didnt do too much real work.

Plug it in, turn on the PSU, hit the power button. Some things spin up some things dont. No beeps because the speaker is busted but the post readout on the fatality board simply read out to mean "power cycle startup". I turn it off, unplug it, and reseat the power switch jumpers. Plug it back in and turn it on. Much to my surprise everything spins up and turns on, but the power button and reset button have no effect, and there is no video output. The GURU pannel shows the room temperature, but doesnt give any reading on what the mobo is doing (which is should >_< )

I try shorting the power buttons jumpers, but that didnt do anything. I unplug the PSU cables that run to the Mobo (there are 2 of them) and they render certain things without power but still seem to bypass the whole power switch circuit somehow and turn everything on without me closing the circuit with the switch.

What. The. Hell.

Bad PSU? Did I kill the mobo(< I hate this possibilty)?

Im ordering a new PSU just because they are cheap, but the mobo is a different story.

As I said, extremely unusual problems. Ideas anyone?

 

Have you checked the switch itself for damage...you did set it down a bit too hard lol.

 

Well after I had all that I tore everything down and gave the case a good cleaning and look over to make sure there wasnt any shorts or noticible burn marks (aah the days of P2's) and put it all back together and had the same result.

Unfortunetely I think its the mobo. If I completely remove the ram, everything still spins up but nothing actualy boots.
And thats without touching the power/reset buttons at all. I can unplug them from the board, and upon flipping the psu switch, everything spins up and wont turn off unless I turn off the psu. (even with shorting the power button jumpers).

 

Well, sounds very much like the PSU is dead. Are you sure that had a sufficient power rating? You might want to see if you can get a better brand of PSU rather than relying on a cheap piece of rubbish which probably isn't doing your components any good.

Also, can you check the power rails with nothing connected?

 

I was just messing with it, and noticed a lot of the fans on the mobo dont turn on under their own power. IE I have to flick them or blow them with air to get them started. The fatal1ty board has 2 OTES fans plus the CPU rig plus a fan for the BIOS.

Im gonna try running it with minimum devices and see if that helps. If this is the solution it will prove the stupid problem theory and I can move on.

Ill get back to you with results.

 

Now that I look at it, it may be the PSU, although I still wonder how the hell it spins everything up without me telling it to via the power button.

Even with just the two unique PSU plugs put into the mobo the OTES and the BIOS fans still have a hard time kicking on. If I have the CPU fan in the CPU fan slot, it wont turn on but if its in a sysfan or backup fan spot it will kick on. The mobo is still acting strange, but I did notice an odour permiating from the output fan on the PSU, didnt smell like carbon burning but it definetely didnt smell right.

Its just a 420W but its old and PSUs have a way of dying. But until I get a new PSU I wont know if this is the cause.

 

Try resetting the cmos jumper and use only one stick of known working memory

 

You know, it really sounds like you've got a short somewhere thats bypassing the on switch....

I don't want to sound patronising but are you sure the back of the motherboard isn't touching metal? i.e. is it on it's risers correctly?

I made that mistake once... the PSU would power everything up and then go "PHUT". I've still got that PSU as a reminder of what NOT to do when putting PCs together

 

Why not check the voltages on the +5v and +12v lines from your PSU? Given the way the fans are behaving, I'll bet that your 12v rail isn't delivering anywhere near that voltage. And if the +5v or +3.3v lines aren't up to snuff, the CPU and hard drives won't work either.

As for the "on" switch on the case: on an ATX mobo, it's just a momentary-close switch. It doesn't interrupt the AC power to the PSU. Pressing the case button closes the switch; closing the switch completes the circuit that tells the mobo to tell the PSU to start/stop delivering power. If the PSU is fried, it could be quite capable of ignoring that signal.