I have an AMD 3500+ Venice on an Epox EP-9NPA+Ultra motherboard. For those of you who don't know this board, it has 3 onboard LEDs that indicate what parts of the board are working correctly and an 80 Port debug 7-segment LED display that provides booting up information. Well, when I press the power button, only the RAM LED lights up, while the CPU and the chipset LEDs do not; the debug LED does not activate at all either. The system fans all spin slightly once the power button is pressed before stopping as well.
My first thought was that my power supply had gone bad, but if that were true, I wouldn't be getting even the RAM LED and the slight fan spin, right? I haven't pulled out the CPU yet to see if it looks burned or damaged at all (I'm not an overclocker, BTW), but since the chipset LED is also out, I'm focused on the motherboard being the source of the problems.
Any ideas? I've had this system a little less than 6 months.
I would suspect the psu. If you have a multimeter, you can test it.
Take the psu out, and have 1 ide drive attached. It can be an optical drive or an old hdd, it doesn't matter. Plug the psu in, and connect the green wire to the black wire, in the main mobo harness. You can then use the meter to test the voltages at the molex connectors. If you dont get close to 12 and 5 volts, your psu is dead.
I don't have one of those meters, and the other PSUs I have don't have the extra 4 pins on them. I pulled out the PSU and there's no smell to it. I just realized that the PSU's fans also didn't spin when the system was turned on, and I'm doubting that any other kind of hardware failure could prevent them from turning. The PSU in question is an Allied AL-A400ATX.
I agree with Endyen - I would consider the PSU suspect. You sure you don't have any extra mobo stanchions installed. The motherbaord FAQ has some great troubleshooting tips for this type of problem - highly recommend you read it and make sure you've tried all the usual suspects.
My case came with fewer stanchions than the board had holes for them, so I doubt it, though wouldn't that have presented itsself as problematic sometime prior to today's refusal to boot as well? It's been running perfectly since I put it together in June.
On and off like that normally indicates a power fault. Usually it's a shorted motherboard caused by improper mounting, but since yours has been running so long that's unlikely. It could be another device that's shorted, such as a hard drive, I've seen them go "dead short" when they die. Or it could simply be a failed power supply.
I tried it without any drives plugged in, and it was still the same result. New PSU will be here in a few days, so hopefully that'll be the end of this. Otherwise, I'll be back here. I'm most worried that it killed my hard drives, really, the rest I won't mind having to replace if necessary.
The psu fans wont spin up? Try jumping the green and black wires with nothing else attached, except the power cord. If it doesn't spin the fans, it's toast. If it does spin the fans , maybe yes, maybe no.
If the PSU fans dont go then I must agree with everyone that its a PSU issue, however for shits and giggles play with your ram change slots and sticks until you've tried every combo twice. That normally gets it working till you can afford a new PSU. If you can afford a new PSU now then ignore me.