dogbreath wrote:

I would guarantee that if the PSU was replaced and the problem goes
away, you would then know what the problem was !

--
Best Regards:
Baron.

On 3 May, 02:27, dogbreath <mr.mxyzp...@att.net> wrote:
yes.. It`s a win-win situation..

suppose you
change PSU, and problem is gone.
But you are still puzzled.. So you change PSU back, and problem comes
back.
Change PSU again, and problem gone.

So you have at least narrowed it down to a problem with that PSU, not
MBRD. (Though sometimes when swapping something fixes it, it can be an
incompatibility between the 2 things, in this case, where one is doing
something it shouldn`t, and the other is being strict/not flexible)

You will have at least narrowed it down to the PSU. Then the question
is how do you narrow it down further.

I see you are into electronics and want to know precisely what
regaridng the PSU, is at fault.. though that is an electronics issue..

Some things you could check on the PSU..

The Purple wire on the ATX connector, that is 5VSB, it has to run in
order for the computer to turn on. So when the computer is not
turning on, measure it. See if it is around 5V. Either stick the
probes into the connectors, or backprobe.

You could check the grey wire (Power Good/OK) But from a recent test,
I have found that my motherboards tend to ignore it anyway. (I have a
junk power supply, I tried cutting the green purple and grey wires and
stripped off a bit of them so I could reconnect them with my fingers,
to see how things were working)

Try taking the power supply out of the machine, grab the atx
connector, use a paperclip to connect the green wire, to any black
wire. Not literally.. but effectively, like by sticking one end of the
paperclip in the hole where the green wire is, and the other end in
the hole where the black wire is. You can use a bit of wire to do
that too. The power supply should turn on, and the fan spin - you can
check fan spinning by putting a hand or if need be, a tissue near it.
You may hear it.

Could check the red(5V),yellow(12V) wires.

You could try removing everything except video card, ram. Does it
turn on now?
How about removing the RAM? It should at least beep I think if no
RAM.

If it is CMOS battery, and I doubt it is, then besides replacing it,
there is a test that involves measuring voltage across it or
something.. I haven`t done that, but should be simple. prob on google.

Of course, do let us know if you do narrow this error down.. or how
you progress in doing so. what you find e.t.c.

On 4 May, 05:33, "jameshanle...@yahoo.co.uk"
<jameshanle...@yahoo.co.uk> wrote:
<snip>
just to add

An obvious thing to do, similar to what sandy58 suggested, turn it on
from the power pins.. It`s obvious to anybody that has built a
computer, or at least put a motherboard in a case and connected a
power button. Turn the computer on with a screwdriver, the
screwdriver touches the 2 pins together. See if that works every time,
or not.

I have never heard of a computer turning on minutes after the button
is pushed.. That is very strange.
<crap>
I have seen computers suddenly turn on,
when the power cord is plugged in. or as a WakeUp set in the BIOS,
from a keyboard key press, or at the network adaptor from a "magic
packet". You may want to try changing the power cord , and
disabling those things.
CPU overheating can cause it to crash or shutdown and not go on for a
while. (speedfan.exe or BIOS could show cpu temp).
I wonder if maybe that is what happens if power_good(grey wire) takes
a long itme to be ready i.e. to send the 5v signal, (even?) after the
power button is pushed. But from my experiments, the motherboards I
have do not even use power_good. So I can`t test that.. and it is a
wild guess anyway
</crap>

jameshanley39@yahoo.co.uk wrote:

A very effective test for the coin cell/CMOS battery 3V, is to put a
yellow LED directly across it. If it glows medium to brightly then the
battery is fine. A bad battery will produce a poor to no glow at all.

--
Best Regards:
Baron.

On Thu, 01 May 2008 14:09:21 -0700, dogbreath <mr.mxyzptlk@att.net>
wrote:

I absolutely agree with everyone that said this is a PSU problem. I
was afraid the PSU was some weird Dell form factor available only
through Dell, if they still support it. But it turns out to be a
standard 250W mini-ATX, common as dirt. I got a 400W version of the
same on order.

Thanks all.

On 4 May, 15:30, Baron <baron.nos...@linuxmainiac.nospam.net> wrote:
that is really cool, I will try that LED thing you mentioned, along
with the multimeter thing i mentioned..

I may even add an LED to my computer bag/toolkit!

jameshanley39@yahoo.co.uk wrote:

I originally discovered the trick when I had to diagnose a BIOS/Clock
problem without a tester/multimeter handy. The case had two yellow
LED's. One to show power and the other HDD activity. So I just pulled
the connector off the M/B and used a paper clip cut in half stuck into
the female bit.

Turned out that the BIOS was corrupt ! Battery 1 BIOS nil.

--
Best Regards:
Baron.

On 6 May, 21:44, Baron <baron.nos...@linuxmainiac.nospam.net> wrote:
I love it.. use the LED from the front of the computer, smash the
front of the case!!
I am in the unusual situation that all the cases I have, I like. I
found one good one , on special offer. and bought 8 (were screwless
chenbro cases). I knew it was good ;cos I saw it advertised on one of
scott mueller's videos - he did have the vids online somewhere free.

I bough 8 good ones so that I never have to go through the hell of
expensive computer cases that turn out to be a load of crap.

Actually, what would do the trick nicely, is ..
Considering the fact that the LEDs on the front of the case and have a
female connector on the end of them.
So If I had a male connector of that size. I could attach long wires
to it and touch them to the CMOS battery with just 2 fingers. That
little gadget (male connector with long wires ) would work with any
case's LEDs and would be non-invasive.

BTW, I notice maniac is misspelt in your EM.

jameshanley39@yahoo.co.uk wrote:

Well spotted ! ;-) Should be correct now.

--
Best Regards:
Baron.