P5P800 - cmos settings wrong; computer dies

[Will R]

Hello,

I just put together a new system with:

Asus P5P800 and a Pentium 630 w/ 500W power supply.

After all components were hooked up, I started up the computer and got a
"cmos settings wrong." The power then died. All I could see was that my
DVD-rom, RAM, and hard-drives were all recognized, which was followed by
the cmos error and shutdown. Never got far enough to actually get into the
BIOS. I tried alt + f2 to flash bios; didn't work -- keyboard, however, is
recoginzed because I can TAB to see detailed POST. Next I took out the
battery and reset the jumpers. I rebooted the computer, which displayed
some message then died. Now, hereafter, computer does not boot at all
(though the standby-led is lit on mobo). I bought another psu, but still
computer does not boot -- not even POST.

The last time I tested the system, I noticed, unlike in the previous test,
that the mobo was extremely hot around the PCI slots (nothing is populating
those slots.) Also, is it normal that the CMOS chip (to the left of the
battery) is marked with a Z or an N, depending how you look at it, in blue
ink?

The PSUs are both 500w: the first one I tried was a Rosewill and the second
one was an Antec.

Any insight into this frustrating problem would be most welcomed.


Thanks,
Will

 

[Paul]

Hello,

I just put together a new system with:

Asus P5P800 and a Pentium 630 w/ 500W power supply.

After all components were hooked up, I started up the computer and got a
"cmos settings wrong." The power then died. All I could see was that my
DVD-rom, RAM, and hard-drives were all recognized, which was followed by
the cmos error and shutdown. Never got far enough to actually get into the
BIOS. I tried alt + f2 to flash bios; didn't work -- keyboard, however, is
recoginzed because I can TAB to see detailed POST. Next I took out the
battery and reset the jumpers. I rebooted the computer, which displayed
some message then died. Now, hereafter, computer does not boot at all
(though the standby-led is lit on mobo). I bought another psu, but still
computer does not boot -- not even POST.

The last time I tested the system, I noticed, unlike in the previous test,
that the mobo was extremely hot around the PCI slots (nothing is populating
those slots.) Also, is it normal that the CMOS chip (to the left of the
battery) is marked with a Z or an N, depending how you look at it, in blue
ink?

The PSUs are both 500w: the first one I tried was a Rosewill and the second
one was an Antec.

Any insight into this frustrating problem would be most welcomed.


Thanks,
Will

If you have extreme heat, that could mean there is an internal
short in the motherboard. Or, it could mean there is an extra
standoff underneath the motherboard, and the standoff doesn't line
up with the normal grounded ring around a mounting hole.

The ring of solder around the mounting hole, and the standoff
are meant to touch, so that is OK. It is when a standoff comes
in contact with an area of the board that is not a mounting hole,
that bad things happen.

You should test the motherboard outside the computer case, a
so-called "cardboard test". If the motherboard is still burning
hot, RMA it, as it has an internal fault. If the motherboard
now behaves normally, something must have been shorting to the
bottom of the motherboard.

Internal faults can be so bad on a motherboard, that the PCB
material will be charred. I hope you don't let it get that
far, as the smell will annoy anyone living with you.

To do the test, you'll need to remove both the motherboard
and the PSU from the computer case. A screwdriver tip, inserted
between the two pins where normally the power switch would go,
should be enough to start it up. Only a momentary contact of
the screwdriver tip should be needed. (Drain any accumulated
static charge from the screwdriver tip, before touching it to
the pins.) To turn the system off again, it is easiest to use
the switch on the back of the PSU.

When doing the cardboard test, I put a thick phone book underneath
the board. That leaves room for the faceplate on the plugin cards,
to hang below the level of the motherboard. Be very careful with
any cables, like the VGA cable leading to your video card, as a
tug on the cable could pull the video card loose. And always unplug
the system, before installing or removing components, to avoid
damaging them. (When a system is unplugged, then you can be
absolutely sure there is no power present. One poster to this
newsgroup had a PSU that continued to run after it was shut off
via the switch on the back, and unplugging removes that possibility.)

On my last two systems, I assembled them on a table first, and
booted into Windows, before trying to put any of the components
into the computer case. It is so much easier to reach stuff while
it is sitting on a table.

Paul

 

[DaveW]

Your motherboard died. Time for an RMA.

 

[Will R]

(e-mail address removed) (Paul) wrote in

If you have extreme heat, that could mean there is an internal
short in the motherboard. Or, it could mean there is an extra
standoff underneath the motherboard, and the standoff doesn't line
up with the normal grounded ring around a mounting hole.

The ring of solder around the mounting hole, and the standoff
are meant to touch, so that is OK. It is when a standoff comes
in contact with an area of the board that is not a mounting hole,
that bad things happen.

You should test the motherboard outside the computer case, a
so-called "cardboard test". If the motherboard is still burning
hot, RMA it, as it has an internal fault. If the motherboard
now behaves normally, something must have been shorting to the
bottom of the motherboard. ....

Paul

Thanks, Paul, for your reply.

I did, in fact, do the cardboard test. The result was basically the
same: it began POST then died. But since I reset the CMOS the system will
not boot at all, and now the smell has gotten stronger. I guess it's
safe to assume that the board is now dead. I will try to RMA it.

If there was a short from the beginnig, would that have caused the cmos
error, rather than just shutting down the system altogether?

Regardless, let's hope the second try will work out. Thanks very much
for your help!

Will