Computer quit

Paul wrote:
Dave Doe wrote:
In article , , Rich
Hare says...
My wife's computer quit on her. Shut it down properly one night and
it refused to boot the next morning. No post, NADA.

Motherboard is an ASUS M3N78. Opening it up and I can see a light on
the motherboard, the fans are all working and I believe the hard
drives are spinning, but there is no signal to the montior (or a
second monitor that I tried).

I would like the opinion of the group whether the problem is:

Before you try anything serious, just try de-powering the motherboard
- ie. pull the power cord out, for about 15 seconds.


A flat (zero volt) CMOS battery (CR2032 in socket)
can prevent some computers from booting. None of my
computers here, suffer from that.

Using a multimeter on the 20VDC scale, you can clip the
black lead onto an I/O connector screw (for ground),
connect the red probe to the top surface of the
disc-shaped battery, and determine whether it still
reads 3.0V or not.

The lowest acceptable voltage is 2.3V.

It will go from 2.3V to zero volts, in about three weeks of
being unplugged from the wall. So the battery knee, when no
other power sources are present, is about three weeks long.

Paul

Well; I violated the first rule of problem-solving, which is to only
make one change at a time, but I got the subject computer to boot up
through the bios, so far.

I checked the button battery (2032) and it was 2.87v, so I said "good
enough" and put it back. I pulled all the connections from the case to
the motherboard, and of course nothing happened because the "on" button
was not connected. Re-connected the "on" button leads and turned the
power supply on, pushed the "on" button and WOW, it booted up right
through the bios (no hard drive connected yet). Sure look like it's
fixed and the proximate cause is the "reset" button.

When I get back to it, I'll try a reconnect of the "reset" leads and see
if it's still a problem or if the switch is bad. Clearly seems like
memory, power supply and processor are OK.

Anyway, would NOT have been able to do it without the suggestions
received here, and a new idea of things to try in a similar situation.

Good Group! Thanks!

Rich

Rich Hare wrote:

Well; I violated the first rule of problem-solving, which is to only
make one change at a time, but I got the subject computer to boot up
through the bios, so far.

I checked the button battery (2032) and it was 2.87v, so I said "good
enough" and put it back. I pulled all the connections from the case to
the motherboard, and of course nothing happened because the "on" button
was not connected. Re-connected the "on" button leads and turned the
power supply on, pushed the "on" button and WOW, it booted up right
through the bios (no hard drive connected yet). Sure look like it's
fixed and the proximate cause is the "reset" button.

When I get back to it, I'll try a reconnect of the "reset" leads and see
if it's still a problem or if the switch is bad. Clearly seems like
memory, power supply and processor are OK.

Anyway, would NOT have been able to do it without the suggestions
received here, and a new idea of things to try in a similar situation.

Good Group! Thanks!

Rich

Continue to keep an eye on the power supply. Power supplies are high
on the list for "flaky behavior".

Eventually you'll need another CR2032. But not today.

And congrats on your repair skills. Your Maytag cap is in the mail.

Paul

On 1/20/2016 10:54 AM, Paul wrote:
Rich Hare wrote:

Well; I violated the first rule of problem-solving, which is to only
make one change at a time, but I got the subject computer to boot up
through the bios, so far.

I checked the button battery (2032) and it was 2.87v, so I said "good
enough" and put it back. I pulled all the connections from the case
to the motherboard, and of course nothing happened because the "on"
button was not connected. Re-connected the "on" button leads and
turned the power supply on, pushed the "on" button and WOW, it booted
up right through the bios (no hard drive connected yet). Sure look
like it's fixed and the proximate cause is the "reset" button.

When I get back to it, I'll try a reconnect of the "reset" leads and
see if it's still a problem or if the switch is bad. Clearly seems
like memory, power supply and processor are OK.

Anyway, would NOT have been able to do it without the suggestions
received here, and a new idea of things to try in a similar situation.

Good Group! Thanks!

Rich

Continue to keep an eye on the power supply. Power supplies are high
on the list for "flaky behavior".

Eventually you'll need another CR2032. But not today.

Change the battery. The voltage is getting into the flaky range.
My computer quit booting somewhere around that voltage. Depends on the
particulars of the computer and the temperature and and and.
If it ain't broke today, it will be later. Save yourself the aggravation.

And congrats on your repair skills. Your Maytag cap is in the mail.

Paul