one long beep, then no post. dead mobo?

[jeffjones]

Working on a friend's home-built rig, and now it won't boot. The problem was intermittent, gradually becoming complete failure.

* sometimes it would boot but with errors (kernel errors)
* sometimes no boot, beeps
* sometimes would boot fine, then suddenly shut off in the middle of web browsing or whatever.

Now, it won't boot at all. It just gives a 4 second continuous beep, pause, then a non-stop beep (will continue as long as you let it). All fans are spinning, including the CPU.

The rig was built in August 2004
Specs:
350w off-name PSU
Asus P4S800
P4 2.8 cpu 800 mhz bus
1 stick, 512 mb Corsair pc3200
ATI 9200
80 GB WD IDE HD
NEC 8X DVDRW
on-board sound

Here's what we've tried so far:

* swapped PSU for known good Antec 420w PSU - results in same beep code

* swapped vid card for know good ATI 9800 Video card - results in same beep code

* swapped cpu for known good P4 2.8 ghz CPU - results in same beep code

* swapped RAM for known good stick of exact same brand and type. - results in same beep code

* tried unplugging all devices, except mobo, video, mouse, keyboard. No go. same beep code.

* tried re-seating video and cpu, nada.

Does this narrow it down to the motherboard? For the life of me, I can NOT find beep codes for this board. Anyone know what one long continuous beep would normally mean?

Thanks for reading

[nutsak]

If you had the manual then the beep codes should be in there, I've googled and couldn't find anything either.

I'd try plugging it all in except leave the keyboard and mouse unplugged. Just have the video card and ram in.

Then I'd find out how to reset the BIOS (either by removing the little battery or via jumper - the manual should tell you this) other wise I'd say it's bung. Also check out this
I doubt that's your problem - but it's worth a look.

Other than that the Asus website pretty much blows for information.

[mystery]

I've found that the beep codes that I've encountered consistently have to do with one of two things:

1) Incorrectly seated vid card. Yea, I know it looks like it's all the way in...but is it REALLY all the way in.

2) slightly incompatible memory. I had a Dell server that I picked up that used a known Intel mobo. Knowing that Dell charged a premium for the memory, I checked out pricewatch.com for the memory that Intel suggested for the mobo. The units I bought did nothing -- and the mobo just fired up with the beeping. After getting on the horn with Dell, their only alternative was to buy Dell memory. I buckled, bought the memory, and the thing has never worked better ever since.

[Aszurom]

Thanks Dell!

Sheesh. That makes me feel better about switching my company from Dell to HP. And I finally got them off Dell servers and onto IBM. Yay.

[jeffjones]

thanks for the replies. I took the further steps of pulling the mobo from the case (in case it was shorting on the case wall), and also pulled the ram and the vid card, and still get same beep code sequence.

Gonna RMA the mobo, I don't see what else it could be.

[Aszurom]

Did you reseat the cpu yet? Sounds like you did everything else but. I'd suck if that was it.

[jeffjones]

Did you reseat the cpu yet? Sounds like you did everything else but. I'd suck if that was it.

Yep, that was in my original post. I also tried a known good CPU of the same brand and speed, and no luck.