Really strange - A7N8X problem?

  • Thread starter Thread starter Vic Baron
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Vic Baron

I have a system with an A7N8X and an Athlon XP2700 in an Antec case w/ 400w
PS. Been running fine for over a year. I'm one of those who do not leave
system on 24/7. Several times, when I pushed the on button - nothing
happened. Took out plug, etc tried again - pushed button - all is well. This
happened several times over a period of the next few months. Then one day,
no matter what I did, system would not power up. Opening the case, I could
see the led on the mobo lit, press button - a blink and nothing. After that
not even a blink UNLESS I unplugged the power cord, plugged it back and
tried again - blink and nothing.

Had a spare PS so I tried it - SAME thing. SO I suspected the mobo - went
out and got an A7N8X-E and installed it - same thing!!! Decided it must be
the case switch so I put the 400w ps back and shut down for the night. No
chance to get a new switch for a few days. Next day, hit the start button
just to check and - it started! That was over a week ago and I have shut it
down and started it back up every day without problem.

I don't mind fixing the problem and buying parts BUT I haven't the faintest
idea WHICH part could be the issue. I will probably get a replacement switch
and keep it handy but I am really at a loss here.

Anyone have any thoughts? I doubt that it's a mobo issue since it happened
with two different ones but it never hurts to ask.

If anyone knows of another forum that I should post this in, I'd appreciate
knowing that also.

Thanx,

Vic Baron
 
Very odd indeed. For informations sake, I have 4 of the A7NX-X boards (love
em) and they all perform flawlessly - overclocked heavily also. And I've had
none of your power problems in different cases and PSU's. I guess a
conclusion could be made to say its either your power-outlet, powercord to
PSU, or youve got some kind of heavy electro-magnetic-pulsing going on
nearby... which is doubtful ;)
 
Yes, it is odd. You mention electro-magnetic pulsing. Approximately 50 feet
from my system is an old satellite dish antenna. Not the new tiny ones -
this sucker is big and black and at least 10 - 12' in diameter. Could this
cause something like that?

I've bought a new house and will be moving around the end of the month so
I'll be interested in how the system behaves after the move. I hadn't
considered any type of interference. BTW, I've swapped power cords, outlets
and even connected to a UPS with no appreciable difference. For now, it's
working.

Thanx for the thoughts -

Vic
 
Try a different power cord, I've seen them go flaky at the PS
connector interface and make poor contact.

--
Best regards,
Kyle
| I have a system with an A7N8X and an Athlon XP2700 in an Antec case
w/ 400w
| PS. Been running fine for over a year. I'm one of those who do not
leave
| system on 24/7. Several times, when I pushed the on button - nothing
| happened. Took out plug, etc tried again - pushed button - all is
well. This
| happened several times over a period of the next few months. Then
one day,
| no matter what I did, system would not power up. Opening the case, I
could
| see the led on the mobo lit, press button - a blink and nothing.
After that
| not even a blink UNLESS I unplugged the power cord, plugged it back
and
| tried again - blink and nothing.
|
| Had a spare PS so I tried it - SAME thing. SO I suspected the mobo -
went
| out and got an A7N8X-E and installed it - same thing!!! Decided it
must be
| the case switch so I put the 400w ps back and shut down for the
night. No
| chance to get a new switch for a few days. Next day, hit the start
button
| just to check and - it started! That was over a week ago and I have
shut it
| down and started it back up every day without problem.
|
| I don't mind fixing the problem and buying parts BUT I haven't the
faintest
| idea WHICH part could be the issue. I will probably get a
replacement switch
| and keep it handy but I am really at a loss here.
|
| Anyone have any thoughts? I doubt that it's a mobo issue since it
happened
| with two different ones but it never hurts to ask.
|
| If anyone knows of another forum that I should post this in, I'd
appreciate
| knowing that also.
|
| Thanx,
|
| Vic Baron
|
| --
| There are 10 kinds of people - those who understand binary and those
who
| don't
|
|
 
"Vic Baron" said:
I have a system with an A7N8X and an Athlon XP2700 in an Antec case w/ 400w
PS. Been running fine for over a year. I'm one of those who do not leave
system on 24/7. Several times, when I pushed the on button - nothing
happened. Took out plug, etc tried again - pushed button - all is well. This
happened several times over a period of the next few months. Then one day,
no matter what I did, system would not power up. Opening the case, I could
see the led on the mobo lit, press button - a blink and nothing. After that
not even a blink UNLESS I unplugged the power cord, plugged it back and
tried again - blink and nothing.

Had a spare PS so I tried it - SAME thing. SO I suspected the mobo - went
out and got an A7N8X-E and installed it - same thing!!! Decided it must be
the case switch so I put the 400w ps back and shut down for the night. No
chance to get a new switch for a few days. Next day, hit the start button
just to check and - it started! That was over a week ago and I have shut it
down and started it back up every day without problem.

I don't mind fixing the problem and buying parts BUT I haven't the faintest
idea WHICH part could be the issue. I will probably get a replacement switch
and keep it handy but I am really at a loss here.

Anyone have any thoughts? I doubt that it's a mobo issue since it happened
with two different ones but it never hurts to ask.

If anyone knows of another forum that I should post this in, I'd appreciate
knowing that also.

Thanx,

Vic Baron
Click to expand...

The green LED on the motherboard, should not blink. It should light up
steadily, when the switch on the back of the PSU is set to "On". When
you press the button on the front of the computer, the LED should stay
on steady. At least it does for the motherboards I've got here.

For the LED to blink, requires that something on the motherboard
draw 1 or 2 amps, and cause the +5VSB to go into current limiting.
It is either that, or the PSU itself has a weak +5VSB circuit, and
it is no longer capable of supplying the rated current. Since you've
changed the PSU and the problem is gone, I'd say it was the PSU.
(Do you have the USBPWR headers set to run from +5VSB ? Or maybe
the keyboard ? Running a bunch of power hungry USB devices from
+5VSB, via a change to the factory default for USBPWR, will add
to the strain the PSU gets while the computer is sleeping.)

I experienced a failure to start a couple of days ago. It required
pulling the plug from the wall, as I think I tried even switching
off the PSU via the switch on the back of the computer, and it wasn't
enough. It could be my PSU thought there was a fault, and it latches
the fault until the power is completely removed. Otherwise, I
cannot explain why it recovered via pulling the plug. (This happened
after an eight hour run of Prime95, so it was warmed up nicely.)
In any case, that PSU has developed another symptom. When I switch
it on, it causes my UPS to beep, and none of the other PSUs, or that
PSU itself, did this in the past. I can still connect other power
supplies, and they don't do this. I don't know if there is some
correlation to my failure to start, and the extra slug of current
the PSU seems to be drawing from my UPS. (What is scary about PSUs,
is they have a very high inrush rating, which is effectively no limit
at all. Now, because the current is so large, the duration is not very
long, before the main capacitors in the PSU are charged. So, having the
UPS beep for that one supply, implies the duration has changed, so that
it is long enough for the UPS to detect as a load fault.)

BTW - The supply I had the one occurrence of failure to start was
an Antec Truepower 480. Pulling the plug fixed it for now. No
trouble since (knock on wood).

HTH,
Paul
 
Thanx for the ideas, Paul. For now, it seems to be working just fine but
when it starts acting up again I'll look at those voltages.

Vic
 
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