this used to be called "Who else thinks it's the mobo" i replaced the motherboard with a brand new one. and still get a long, repeating beep that never ends. nothing is plugged into the BRAND NEW MOBO except a processor and power. the fans and such all turn on, so i'm getting power. it's a celeron 1.8 ghz, but i've never seen a proc go bad less you throw it at a wall or something.
This happened to me once, my problem was my processer was too hot and was overheating so it started to beep. I got another fan to cool it and everything was fine. The beep did freak me out and i just dealt with it untill a friend came over a few days later and helped me out, lucky for me because if it had run awhile longer my procesor would have been destroyed. Do you have a proccesor fan?
The fact that the "fans and such turn on" does NOT mean that the power supply is OK. It only means that there is some output from whatever power rail runs the fan. A PC power supply has at least 4 separate power outputs (+5V, +12V, -5V and -12V), and ATX form factor supplies add a +3.3V and standby +5V to the mix. In addition, the supply generates a logic signal called "PG" or "Power Good", when all outputs are within limits. ALL of these outputs need to be present for the machine to boot properly. As I suggested in the old thread, you should have verified the outputs from the power supply with a voltmeter BEFORE replacing the mobo. If the supply was the problem, you might have saved the cost of a new mobo. And if the supply failed in such a way as to output an excessive voltage on one of the rails, you may have just fried the new mobo or the CPU! A suitable voltmeter is available from RadioShack or Home Depot for less than $20. This is a basic tool that should be in the toolbox of anybody who is trying to repair PCs. A trained monkey can just swap parts blindly, but a true technician makes the needed tests to figure out what the problem is.... If the power supply checks out, then process of elimination would leave the CPU, but like you, I haven't seen one go bad unless killed by something like poor cooling, overclocking, overvoltage, or improper installation.
no...no periphals plugged in... I got lucky this time ellis, i went and got a multimeter and tested the voltage coming off the power supply, and it was all normal. just the +/-12 and +/-5. so it would lead a guy to think ok, you're on a brand new mobo, power is normal, must be that proc? nope. found a replacement from a working box, and got the same error. i got nothin. gremlins i expect.
Is the PG signal present? Should be a logical "1" (near +5V) if the supply is OK. Usually a grey wire in the bundle that feeds the motherboard. Are you SURE that this machine will boot without RAM and a keyboard connected? Many recent boards will not. If in doubt, install the RAM, making sure it is in the proper slots, and of the right type/speed. Does the mobo require jumpers to be set for different CPU types? If so, are they set properly? I would take the suspect CPU and plug it into a known good machine as a test. Booting the new mobo from another power supply would be a good test, as well. No need to bolt it all into a case, just plug it all together on a (nonconductive!) tabletop. Have you checked for the really stupid shit, like a reset switch stuck down? CMOS battery good? Mounting screws not shorting any traces to ground?
Oh man, I had this really shitty case once with a crappy facia that was a bitch to fit. Took me ages to work out why the fucker wouldn't boot, and it was all down to the facia jamming the reset switch in place!
