Moan and Groan

[shankle]

Please help if you can or tell me where to look for more info.
See attached.

[dedndave]

i know it can ruin your day to see something die at your own doing
well - truth is, you may not have done anything wrong - it was going to fail anyways
that's supposed to make you feel a little better   :P

the first thing to check is the power supply voltages
XT and AT power supplies provide +5, -5, +12, and -12 VDC
the tolerance should be +/-5%
these are from days of old when a combination of TTL and NMOS/PMOS IC's were used
+12V is also often used for fans

NMOS/PMOS IC's have faded into the past
and, along in the late 90's, Intel et al figured out that lower operating voltages were conducive to faster slew rates
so, modern CPU's often run on something around +3 VDC
some modern power supplies may provide that voltage, as well (3.3 or 3.2, usually)
however, many systems have a small regulator circuit on the motherboard that derive the 3 V supply from the +5 output

checking voltages is a first good step
if you don't have a meter, radio shack sells a couple that are usable
one is about $10 - and the next one is about $15
i suggest the $15 meter

beyond that, there are a million things that can cause the symptoms you are seeing
it is likely that the manufacturer will repair the computer for $75 to $100 plus shipping
or - you may be able to replace the motherboard
HP is pretty good about customer service

i would probably go the next step
that is to reduce the system to the minimum number of components
remove extra boards that are not needed to boot
you need a motherboard, mouse, monitor, keyboard, power supply, hard drive - as a minimum
then, i might swap known good components out
by a process of elimination, you can determine which of those components is failed

[shankle]

Thanks Dave for taking your time to respond. Been banging head on wall.
Much more and I'll either need a new head or someone to fix the wall :(
I noticed today that the mouse only comes on at startup for 1 second then
dies. I changed the USB to another connection and no difference. I will
try another keyboard/mouse. Have changed the HD. No difference.
Hate to spend the $90 to $150 on a MB if I don't need to.
Will keep plugging....

[dedndave]

hard to say, but it sounds like the power supply shuts down
make sure you don't have something on the USB that is shorting

the power supply may be shutting down because it's bad
or because something is drawing too much current, which causes it to shut down
it can be difficult to tell which is happening, thus the swap known-good components method