I am trying to repair a computer with an AMD 1.7GHz chip on a Elite
K7VMM+ mb with a 300W PS, using a 20GB disk with Win2000.
That board might have bad capacitors, examine them for signs
of swelling or leakage.
What make and model of PSU? If it is a very low end 300W
PSU it may not be suitable for long term use and has failed.
When it
starts up, nothing displays on the monitor (no start up sequence).
Classic "no POST" scenario. Unplug PSU from AC for 10
minutes, while you have the battery removed (or use clear
CMOS jumper while AC is still disconnected).
When was system last working, how long had it worked and
what had changed? Did it just work everyday with no changes
then one day it wouldn't turn on, or?
Examine cables, cards, fans, etc, trying to find a failed
part.
The
HD, monitor and cable are fine, as I tested them on another computer.
Which "cable"?
Don't even hook up the hard drive, try to get system running
in a bare minimum configuration (towards POSTing).
You then only need 1 memory module, CPU, heatsink/fan and
video - except video appears to be integrated on this board?
If so, use the integrated video or you could try a PCI video
card but avoid using a higher powered AGP card if your PSU
is straining itself.
The power supply seems to power the HD, as it spins. The lights
flicker on the mb .
If you have a multimeter, it wouldn't hurt to take voltage
readings, especially of 5V, 12V, 3.3V, and 5VSB.
Basically, I replaced the mb with an identical one I bought off ebay.
Bad way to test because we can't be sure the one bought off
ebay is working. I mean, would work even if everything else
does. If a board sits around the battery may drain (check
it's voltage too, AND make sure the clear CMOS jumper is in
the right position- sometimes ECS ships boards with the
jumper in the "clear" position and the installer has to
change it).
I also changed the chip with another one off ebay.
This is another unknown variable, ideally you would only
swap in known good parts (or have another way to prove they
work).
I tried using a
150W watt power supply, just to see if anything would show up.
150W PSU may easily be insufficient capacity, it is
"possible" your 150W PSU works fine but can't power this
parts combination, and your other PSU is bad. We can't
conclude this though, there are still a lot of other
possibilities.
Still
nothing shows up. I suppose I should try the mb & chips on another
machine?
Yes if possible, though try the things I'd mentioned above,
and leave all cards, cables, etc, disconnected from the
board and PSU for the time being, and use a screwdriver or
similar to turn the board on by carefully shorting together
the power-on pins (see motherboard manual if you can't tell
which two pins.
Is it possible that the power supply is faulty, but not failing
completely?
yes, possible but not enough evidence to know one way or the
other yet. If you wanted to consider odds, the odds are the
original failure was your motherboard or PSU, unless the CPU
fan had failed or the heatsink fell off. You can then rule
out other parts by disconnecting from board and PSU as
mentioned above, then clear CMOS again with AC disconnected
before retrying them.
Does anyone know of sites which offer PC diagnostics help.
Besides what I've mentioned, there's not a lot more you can
try before swapping known good and viable (in the case of a
PSU with decent quality and capacity) parts into that system
or swapping the questionable parts into a known good system.
You might leave your PSU disconnected from AC for a few
minutes and open and inspect it, some faults are visible
(like capacitors, particlarly on the cheaper PSU they will
fail first if the fan didn't (or especially if the fan did).
