G
Gareth Church
fine.dryOtto said:
Sorry, my short attention span means I couldn't read the whole post. Going
by those symptoms though, I'd say it is motherboard, CPU or RAM. Since you
tried a new CPU, it's a fair chance it's not that. Like you, I thought if it
was a problem with RAM the machine would at least boot. But I had a similar
problem a while ago, and the tech guy from the company I bought the gear off
was sure that if the RAM was dodgy it was entirely possible to get these
symptoms. In that case it was the motherboard though. That would be my main
suspect.
It could also be a power issue. Just because the PSU is new doesn't mean
it's not causing the problem. I have had the same symptoms as you on another
machine, and in this case it was the PSU. When you first turn on a power
supply the power output fluctuates a bit for about a third of a second,
after which it stabilises into a normal output. The PSU sends a message to
the CPU not to start booting, and only after its power output has settled
down does it allow the CPU to boot (it stops it from booting by constantly
restarting the CPU, if you care). Anyway, the net result of this is that if
there is a problem with this aspect of the PSU it is possible for it to
constantly tell the CPU to reboot itself, leaving you with a system that
powers up but does not boot. In my case hitting the reset switch after a
second or two will cause the machine to boot, but this isn't neccessarily
always the case. If you want to find out more about this, go to google and
search for "power_good signal".
Gareth