P4P800 Deluxe failing

[Peter Huish]

I have a P4P800 Deluxe motherboard that has failed - symptom being that
the system will simply not start. This is the second motherboard that
has failed due to the same symptoms.

I am wondering how common this is and also whether I should cut my
losses and find some alternative motherboard.


thanks

pete

 

[Dave Hines]

Is green light on MB lit?
Is PSU fan turning?
If both are yes - disconnect all devices that draw current - except
CPU/fan, boot drive and video card. If no joy - reset BIOS jumper on the
MB. You can even remove either the video card or CPU to see if MB will
detect a missing component on POST. I've had similar problems in the
past with older MB's - all PSU related. (VCore voltages were always
below spec when I had problems). Removing load on the system brought the
MB back to life.

Good luck,
Dave - N2LAK

 

[Paul]

I have a P4P800 Deluxe motherboard that has failed - symptom being that
the system will simply not start. This is the second motherboard that
has failed due to the same symptoms.

I am wondering how common this is and also whether I should cut my
losses and find some alternative motherboard.


thanks

pete

Is it a revision 1.02 motherboard ?

Do the fans spin, or does pressing the button not do
anything ?

If you remove the AGP video card, do the fans spin then ?

Is the green LED lit on the motherboard ? That indicates the
PSU is giving +5VSB, when the switch on the PSU is in the "ON"
position. If the green LED is not lit, meaning no +5VSB is
available, then the motherboard will not be able to start, and
that could be a power supply problem.

There was a problem with revision 1.02 motherboards, where
apparently Antec power supplies would not work reliably, if
at all, with the P4P800 Deluxe. Asus figured out what the
problem was, or at least they were able to ship a motherboard
to replace a couple people's revision 1.02, so they do know
there is something that needs tuning. If you are using an
Antec, you could switch to another brand of power supply,
being aware though, that Antec doesn't make power supplies,
and ChannelWell Technologies (CWT) makes them under contract.
CWT supplies are available under multiple brand names, so that
makes it a bit difficult to shop for a replacement, without
getting potentially the same supply.

As near as I can determine from looking at component datasheets,
the problem is with the P4P800 Deluxe Vcore circuit. It has
some protection features, like overcurrent detection and the
like. My _hypothesis_ is the way the voltage ramps up on the
CWT supply, causes the Vcore circuit to mistakenly determine
an overcurrent situation has happened, and the Vcore circuit
latches in the off state. This happens within the first
one second of operation, and with no Vcore output, the processor
cannot run. Finding a different brand of power supply, will
have a different rise time on +12V, and that might be enough
to "dodge the bullet".

Paul

 

[Peter Huish]

Is green light on MB lit?
Is PSU fan turning?
If both are yes - disconnect all devices that draw current - except
CPU/fan, boot drive and video card. If no joy -

reset BIOS jumper on the MB.

Is this the Clear RTC RAM jumper or is there another one that I am
missing? My MB manual only mentions 4 Jumpers - keyboard power on, SMB
2.0 and USB device wakeup plus the Clear RTC RAM one


thanks

 

[Peter Huish]

Is it a revision 1.02 motherboard ?

I don't know. I cannot seem to be able to see a version number on the
top of the board. Where is it usually located?

Do the fans spin, or does pressing the button not do
anything ?

The fans spin (both on the power supply and the cpu)

Is the green LED lit on the motherboard ?

Yes it is on.

There was a problem with revision 1.02 motherboards, where
apparently Antec power supplies would not work reliably, if
at all, with the P4P800 Deluxe. Asus figured out what the
problem was, or at least they were able to ship a motherboard
to replace a couple people's revision 1.02, so they do know
there is something that needs tuning.

This my second motherboard (I had the same problem with the earlier
board).

In both cases the system faled after an extended period on non-use.


thanks for your help

 

[Paul]

Is this the Clear RTC RAM jumper or is there another one that I am
missing? My MB manual only mentions 4 Jumpers - keyboard power on, SMB
2.0 and USB device wakeup plus the Clear RTC RAM one


thanks

On most boards, this jumper is labelled CLRTC, because it "clears
the real time clock". But, the same block of circuitry in the
Southbridge also contains the battery backed CMOS memory, which holds
BIOS settings.

Unplug the computer before clearing the CMOS. The green LED should
not be lit while playing with CLRTC. This is because a dual diode
can get burnt by the shorting of the CLRTC, and unplugging the power
prevents that from occurring. Follow the procedure in the manual
for CLRTC.

As the board has worked for you, for a while, maybe this is some
other kind of fault. Have you listened to the Voice POST, by
plugging an amplified speaker into the lime colored, Lineout connector
on the back of the computer ? I expect it is probably saying
"Systen Failed CPU Test", and at that point, you don't really
know which component is failing. It could be a weak power supply
(+12V on the low side), it could be the Vcore circuit has failed
somehow (look for visual evidence, leaking caps, burnt MOSFET, etc),
or it could be the CPU that has failed.

Does the CPU run abnormally hot, indicating it is drawing more
power than normal ? It is possible something you are plugging into
the motherboard, is stressing the board and killing it. There are
many possibilities.

Paul

 

[Dave Hines]

Is this the Clear RTC RAM jumper or is there another one that I am
missing? My MB manual only mentions 4 Jumpers - keyboard power on, SMB
2.0 and USB device wakeup plus the Clear RTC RAM one

YEP! remove the battery as well - see your manual for details.

 

[Peter Huish]

As the board has worked for you, for a while, maybe this is some
other kind of fault. Have you listened to the Voice POST, by
plugging an amplified speaker into the lime colored, Lineout connector
on the back of the computer ? I expect it is probably saying
"Systen Failed CPU Test", and at that point, you don't really
know which component is failing.

This is exactly what it is saying

Does the CPU run abnormally hot, indicating it is drawing more
power than normal ?

I don't believe so but that is not based on any solid evidence. The
only notable occurrence is the fact that in each case where the board
failed, it was after a period of inactivity.

It is possible something you are plugging into
the motherboard, is stressing the board and killing it.

The only other card in the system is a video card and removing it did
not make a difference


thanks

 

[ñíñjà¤têç]

the rev# is either printed on the pcb or on the side of the expansion
slots.if you have no number, then you may have an asus clone board...

that being an extreme case, you may have reverse polarity on the
power feed and you can test this by having a good qaulity surge
protector on the power feed. (green light good, red light bad...)

lastly ,try this to rule out any possibilities:

-different power supply
-different cpu
-pci video card


it would be a rare occurrance that 2 boards had the same problem with
your setup, chances are likely it is some other piece of hardware or
your local power is the culprit...

 

[Roy Coorne]

ñíñjà¤têç wrote:
....

it would be a rare occurrance that 2 boards had the same problem with
your setup, chances are likely it is some other piece of hardware or
your local power is the culprit...

Unfortunately, I had a similar experience: a P4P800_D failing without
any rcognizable reason after about six months... the replacement
failing after about four months... both had no additional marking,
i.e. were Rev.1...
A P4P800 Rev.2 still works...

Now I try other brands... other mothers have beautiful boards, too;-)

Roy