A7N8X Intermittent problem - no boot activity

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tgowett

I have a mysterious recurring problem. I built the PC in October 2003
with an A7N8X-Deluxe rev 2. Over the past year there have been a few
times where the PC halts, screen goes black and when it tries to reboot
it says system failed cpu test. I try to cold boot and it still says
failed cpu test. I cannot hear any drive activity and there is no
display on monitor. It will stay like this until I reseat the cpu then
it boots fine. I have replaced cpu and memory. I currently have a
retail package AMD cpu and heatsink, and name brand memory that is
rated to be fine with this board. I have run the probe which shows
temperature is always fine. The only apparent issue is how the cpu is
seated. It started doing this after 3 months of use. First time I
reseated the cpu took care of problem for 6 months. Recurred again,
reseated cpu and no problem for 3 months. Now it recurred in 1
month. This last time, I only wiggled the heatsink and it took care of
the problem, but only for two days. Does anyone have any advice? I am
tempted to just replace with a different brand of mobo. For now, I
have sent the same message to Asus support but I am not holding my
breath for a useful answer.
Thank you.
TG
 
[email protected] said:
I have a mysterious recurring problem. I built the PC in October 2003
with an A7N8X-Deluxe rev 2. Over the past year there have been a few
times where the PC halts, screen goes black and when it tries to reboot
it says system failed cpu test. I try to cold boot and it still says
failed cpu test. I cannot hear any drive activity and there is no
display on monitor. It will stay like this until I reseat the cpu then
it boots fine. I have replaced cpu and memory. I currently have a
retail package AMD cpu and heatsink, and name brand memory that is
rated to be fine with this board. I have run the probe which shows
temperature is always fine. The only apparent issue is how the cpu is
seated. It started doing this after 3 months of use. First time I
reseated the cpu took care of problem for 6 months. Recurred again,
reseated cpu and no problem for 3 months. Now it recurred in 1
month. This last time, I only wiggled the heatsink and it took care of
the problem, but only for two days. Does anyone have any advice? I am
tempted to just replace with a different brand of mobo. For now, I
have sent the same message to Asus support but I am not holding my
breath for a useful answer.
Thank you.
TG
Click to expand...

The product has a warranty. Maybe you can arrange to RMA it ?
I think in my country the warranty is for three years.

It could be a grounding problem on the underside of the
board. Try building up the computer outside the case
(the so-called "cardboard test"). Removing the motherboard
from the computer case, and sitting it on a large book,
will provide the support to allow you to plug in the rest
of your components. Only the AGP and PCI cards will be
dangerously loose in their sockets, so do not tug on the
cards or connectors while the PSU is plugged in and
the green motherboard LED is glowing.

With the system assembled and booted outside the case,
hold the motherboard firmly and apply a little pressure
to the HSF/CPU combo. See if the contact problem still
happens. If you cannot reproduce the problem, it could
be that one of the brass standoffs was shifted from its
ground ring on the bottom of the board, and the standoff
grounded a signal conductor by accident.

I always try to line up the mounting holes to be concentric
with their standoffs, to reduce the risk of a short. That
makes it hard sometimes to fit an AGP card into its
socket, so this will be a compromise between having a good
smooth fit for cards into their slots, versus not shorting
something on the underside of the board. The metal ground
ring on the bottom of each mounting hole, is meant to contact
the brass standoffs, so that part is no accident. It is
just when the standoff touches something running adjacent
to the ground ring, that you can have problems.

If this is a CPU socket problem, return the board under
warranty. In some countries, you go to your vendor first,
to do the return, while in later years of the three year
warranty, you contact Asus and do it there. A return with
Asus takes maybe three weeks, until a replacement ships,
so it helps to have a backup computer during this period.
Between your vendor and Asus, someone should be able to
handle the RMA.

HTH,
Paul
 
What about the cardboard washers? I thought the brass stand-offs were
screwed into the mobo plate, the cardoard washers on the stand-offs,
mobo on top next, then the retaining standoff to hold the mobo in
place. Do I have this wrong. It's been a while since I put it
together so I don't clearly recall how I did it and I'm not at my PC
right now. What should the proper order be?
TG
 
[email protected] said:
What about the cardboard washers? I thought the brass stand-offs were
screwed into the mobo plate, the cardoard washers on the stand-offs,
mobo on top next, then the retaining standoff to hold the mobo in
place. Do I have this wrong. It's been a while since I put it
together so I don't clearly recall how I did it and I'm not at my PC
right now. What should the proper order be?
TG
Click to expand...

On my home computers, I place the brass standoff on the
motherboard tray. Then, lay the motherboard right on
top of the brass posts. The brass posts are meant to
be touching the tin/lead contact area (the plated hole)
on the motherboard. The motherboard is grounded on purpose,
to help reduce RF emissions from the board.

You could use a cardboard washer if you want, but it is likely
the screw is still conducting anyway. The cardboard washer
may prevent the post from touching things it shouldn't,
so I suppose the washer would not be all bad.

You have to be careful not to change the distance the
motherboard is, above the motherboard tray. If you
lift the motherboard, by stuffing things under it,
it will throw off the alignment of PCI and AGP cards.
The cards will end up "tilted", and if the tilt is
severe enough, the wrong pins could make contact in
the PCI or AGP slots.

Paul
 
Paul,

Thanks for the time and comments. I finally gutted the PC and
inspected it. I did have the washers on top of the board, not under it
as I had originally thought. The best I can tell is that the screw
securing the oblong hole in the corner by last PCI slot appears to have
been off center from its washer and may have had contact with the
board. Not sure. In any case, I pulled it all out and put squares of
electrical tape on top of the stand-offs under the board. I positioned
the mobo then put another square of tape (this time folded over on
itself to try to keep the gunk off the board) over the hole of the
board, with washer then screw. I made the squares large enough so that
no possible overlap of the screw head could touch the board without
having it cover anything that might produce heat. Lastly, I cleaned
the cpu and kooler with alcohol and re-applied fresh thermal paste.
It's been up and running for 4 days and Asus probe logs look good, so
far. Thanks again, Paul.
TG
 
Well, the problem has returned after working for three weeks. No boot.
The drives don't even spin up and the light on the 2nd CD drive stays
on. So now I am considering replacing the motherboard with a Gigabyte.
 
I had a K8V delux that had the same problem. About twice a month it
would not boot . I took it back to the company that built it for me
and they sent it back to the orginal manfacture. Tehy claimed it was a
bad bios flash and reflashed the bios. So far 2 months later no
failure to boot.
 
Terry said:
Well, the problem has returned after working for three weeks. No boot.
The drives don't even spin up and the light on the 2nd CD drive stays
on. So now I am considering replacing the motherboard with a Gigabyte.
Click to expand...
I have not seen your original post. I just fixed a machine doing this buy
reseating all the connectors. Also test the memory. Certain locations of
memory are critical and can cause a no POST condition. These boards are
sensitive to some brands of memory. I can't use Infineon. Samsung seems to
work.

bg
 
Did you flash the BIOS before this started happening to you? I would
expect a bad BIOS flash to show problems soon after flashing. I will
try flashing with a new download.
 
Reseating the cpu is the usual temporary fix. Yet it keeps recurring.
I bought the board as a cpu/ram/mb bundle from a vendor. After
troubleshooting it a while I replaced the cpu and ram with an amd 2700+
and 2 modules of Corsair ddr 2700 512MB from compusa. I believe the
corsair memory should be okay with this mb and I have verified they are
in the right slots per Asus doc. I think this leaves me with just the
power supply or mb. Am I correct? Since I can make the problem go
away for a while just by giving the kooler a bit of a push and wiggle I
am thinking that it is most likely the mb. Am I wrong or missing a
consideration?
 
Terry said:
Reseating the cpu is the usual temporary fix. Yet it keeps recurring.
I bought the board as a cpu/ram/mb bundle from a vendor. After
troubleshooting it a while I replaced the cpu and ram with an amd 2700+
and 2 modules of Corsair ddr 2700 512MB from compusa. I believe the
corsair memory should be okay with this mb and I have verified they are
in the right slots per Asus doc. I think this leaves me with just the
power supply or mb. Am I correct? Since I can make the problem go
away for a while just by giving the kooler a bit of a push and wiggle I
am thinking that it is most likely the mb. Am I wrong or missing a
consideration?
Click to expand...
I'd say you are correct as there could be a bad solder connection on the
board.
bg
 
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