Motherboard went silent--fans and hds spin but no bootup.

[jsteph]

Hi all,
I have an Asus M3N78 with an AMD 9850 phenom quad core processor. I just found it dead. I typically leave the machine on 24/7, I came downstairs and it was off. I went to turn it back on and I hear the cpu and gpu fans start, and the hd's spin up, but no 'beep' and no boot screen.

There isn't even the green led from the power button, nor the red led from the hd terminal on the mb. The motherboard led does work howerver, it is green when the power-supply switch is on.

I checked the connections for the PC speaker, the reset sw, the power leds, all that crap, it's all connected firmly to the correct terminals. I've also cleared the cmos and the rtc and put a new battery in it.

The power button works obviously because when I turn it on the fans start, when I hold it for 4 seconds the fans turn off. But no front-panel leds, no beep and no boot.

It's not overclocked, it runs fairly cool. It wasn't doing anything (that I know of) at the time, it would normally just be idling.

I've tried pulling the vid card to force a beep code, I pulled the memory to try and force a beep code too, but nothing. It just seems that when I hit power the hd's spin up, the fans go on, but no lights and no booting. Could this be a dead cpu, dead mb, or could it be something as simple as that little toggle-power switch?
Thanks,
--Jim

 

[cmeagan656]

I'd double check your power on switch connections.

I've had this happen intermittently, although not the dying while it was powered up. In my case, I don't leave my computer on 24/7 so it happens when I power on. I get the same symptoms as you - the fans start, no beep, no boot, no video.

In my case, it seems to be the power on switch, despite appearances. It seems to be that if I don't depress the power on switch far enough the fans come on, the DVD drive is recognized (blue led comes on) and not much else happens. When I check the event logs there is nothing there. It is as if the computer was never powered on. The event log service doesn't even start. When I hold the power on switch in for 5 seconds the computer powers off.

BTW, I also have an Asus mobo but I have Intel Core 2 Duo processors.

I had my system built so I'm waiting for the builder to come by and take a look at the power on switch connections.

Hope this helps.

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[BadBigBen]

Cmeagan has a valid point, in that it could be the PWR BUTTON...

But my bet on it is that the PSU has taken a dive and needs replacing...

since the fans are working, then the 12v rail is still functioning, but most likely either the 5v or 3.3v rails went south on you...



Ben
"If it works don't fix it! If it doesn't use a sledgehammer..."
How to ask a question, when posting them to a professional forum.
Only ask questions with yes/no answers if you want "yes" or "no"

 

[goombawaho]

It can't be the power switch or button because "I went to turn it back on and I hear the cpu and gpu fans start". In other words, SOMETHING happens when the power switch is pushed. A power switch or button problem would yield NOTHING happening.

More likely - power supply as stated. Try another one if you can beg/borrow/steal. Or power supply tester.

 

[jsteph]

Thanks everyone for the input. However, it's starting to look like a 'bad' motherboard...whatever that entails.

I put in a known-goog power supply and front panel and I get the same thing. So I'm going to get mobo and cpu, if the mb fixes it with my current chip, I'll return the unopened cpu.

The quandry is that since I'm getting a new one, I want to upgrade the mobo and maybe even the cpu. But so many of the new mobos are DDR3, and I have an 8gig investment in DDR2 mem which I don't want to waste. So I want to upgrade from the 'regular' phenom x4 to either a Phenom II x4 or an intel i5. So does anyone know of a 'transitional' intel i5 compatible mobo that has both ddr2 and ddr3 slots?
Thanks,
--Jim

 

[jsteph]

Ok, post-mortem:

I was indeed the mobo. I just picked up a new one, same model, swapped it in and I'm up and running. I decided not to upgrade now because I don't have time to really decide how to go about it while keeping the ddr2 mem.
Thanks everyone,
--Jim

 

[goombawaho]

Bummer. Probably a good idea to stick with your current RAM/CPU investment.