Computer Power Cycle Problems

[jcbrief]

I power up my computer, and its fine. When I power it down (not just restart) it won't power up at all. No display, No Beeps, No Post, nothing. If I let it powered off for some hours (at least 4+ I would guess) it will then power up.

Things I've tried w/o it helping:

CMOS defaults,

replacing memory, new memory even in a different slot,

Removing all daughter boards, even swaping video card,

disconecting all drives and their power,

trying another power supply,

removing all power, power supply switch off, and removing power plug,

Other things I've tried:

CMOS fail safe works better, but still has problems. Sets the CPU to 1100Mhz.

When it works I don't notice any problems.

I've run a burn in test for 30 minutes w/o any errors.

W/o another CPU I can't determine if the problem is the CPU or the motherboard, at least thats what seems to make sense. I would appreciate any help in determining what to try next to figure out what is the problem.

EPOX 8RDA+ AMD Athlon XP 2500+ 1G Ram

Win2k

1.833GHz

Thanks,

Joe.

[rendrag]

well, it seems you've exhausted your options short of swapping a CPU or motherboard. My initial reaction is it's a motherboard issue, not a CPU issue, but it's tough to say.

Any chance you could buy a CPU locally, test the system out, and then return the CPU after you've found the source of the problem?

[jcbrief]

Any chance you could buy a CPU locally, test the system out, and then return the CPU after you've found the source of the problem?

Thanks for your reply.

I've been trying to find a CPU that I can test the motherboard with.

Joe.

[big poppa pump]

What kind of PSU do you have?

[jcbrief]

PSU = Antec SL350 350W

But I have swaped out to another PSU and still had problems.

When it fails I often get a "C1", Post cmos error = Detect Memory.

I have swaped memory, and slots, 128 meg strip even, totaly away from 2 512M strips

but when I took memory out, no mem strips, got post no-memory error.

A thought, if the cmos-post does detect memory, but address/data bus's (not mem strips, but hardware on motherboard to CPU) has problems, then when post code switches to ram stack using memory sticks, it may go away. But I can usually still power down the motherboard by holding the power button down for some seconds. I don't know what that mechinism is though. If its totaly hardware, or software.

Joe