New Dell CPx Motherboard won't POST

Hi all,

I purchased a replacement motherboard for an old Dell CPx laptop. I
have a lot of experience with desktop repair but laptops are new to
me. I used the Dell service manual as a reference. Replacement of
the board was painless. When I turn on the laptop, the power light
comes on but I have a black screen and it never begins to POST. The
mobo is identical to the original. I'm certain the CPU is seated
properly as is the RAM, as I reseated them more than once. I get no
error beeps. I've double and triple checked the other connectors for
the palm rest, keyboard and display assemblies. Common sense tells me
when a board won't POST and won't beep, it's a dead board, even if the
power light lights up. I wanted to check with the group to see if I'm
missing something. I've never had a CPU go bad so I suppose that's
possible but I recall that with a bad CPU, you still get an error
message on the display indicating no CPU. Any opinions are
appreciated other than the obvious that it's time to get a new
laptop....

Thanks,

Bob Kruse

Bob Kruse wrote:
> Hi all,
>
> I purchased a replacement motherboard for an old Dell CPx laptop. I
> have a lot of experience with desktop repair but laptops are new to
> me. I used the Dell service manual as a reference. Replacement of
> the board was painless. When I turn on the laptop, the power light
> comes on but I have a black screen and it never begins to POST. The
> mobo is identical to the original. I'm certain the CPU is seated
> properly as is the RAM, as I reseated them more than once. I get no
> error beeps. I've double and triple checked the other connectors for
> the palm rest, keyboard and display assemblies. Common sense tells me
> when a board won't POST and won't beep, it's a dead board, even if the
> power light lights up. I wanted to check with the group to see if I'm
> missing something. I've never had a CPU go bad so I suppose that's
> possible but I recall that with a bad CPU, you still get an error
> message on the display indicating no CPU. Any opinions are
> appreciated other than the obvious that it's time to get a new
> laptop....
>
> Thanks,
>
> Bob Kruse

Use a different ram chip.

On Sun, 07 Oct 2007 13:43:52 GMT, Nuttar Buttar
<> wrote:


>Use a different ram chip.

Excellent suggestion. The laptop has two, 128 mb sticks. When I
first got the laptop, I tried pulling one stick and then the other
with no improvement in behavior. I should mention that the initial
problem was that the laptop would lock up within 60 seconds of boot.
Sometimes I could get into Windows but sometimes not. I removed the
hard drive to rule it out and had the same problem going into the
BIOS. I have no spare parts for this laptop so after removing all
the cards and the hard drive and swapping out the ram, I decided the
problem had to lie either with the processor or the motherboard. I
decided to try a new board because I found them cheap on ebay. This
could be a processor issue too.

Bob

Hi

Have you tried changing the small power board that plugs in to th
mobo? That may well have died

--
sionyn

On Mon, 8 Oct 2007 04:16:49 -0700, sionyn <> wrote:

>
>Hi,
>
>Have you tried changing the small power board that plugs in to the
>mobo? That may well have died.

No, but I do have the power board from the other motherboard I can
try. Thanks!

Bob

On Mon, 08 Oct 2007 18:37:32 -0700, Bob Kruse <>
wrote:

>On Mon, 8 Oct 2007 04:16:49 -0700, sionyn <> wrote:
>
>>
>>Hi,
>>
>>Have you tried changing the small power board that plugs in to the
>>mobo? That may well have died.
>
>No, but I do have the power board from the other motherboard I can
>try. Thanks!
>
>Bob

The motherboard actually has two cards that plug into it. One is the
size of two postage stamps and has the lights for power, hard drive,
etc. The other card is about the size of a playing card and sits
right above the middle of the motherboard. Since I have another
identical mobo, I swapped out both cards and the heatsink and fan, one
at a time, with no change in results. Then, I put the old motherboad
back in with the cards and heatsink and fan from the other board.
This time, I can get into the bios again but as before, it lasts a
minute and then locks up.

So, on the replacement board, I can't get into the bios at all. The
screen is black which leads me to believe it's a dead motherboard.

It could have been one of the cards attached to the motherboard except
that I changed them all out and had the same result.

Reinstalling the old mobo gets me back to a partial boot before lockup
but that tells me my problem is probably not the CPU since the results
are different when the same CPU is installed on different but
identical boards.

So I stand by my original theory that the first board was failing and
the replacement board was DOA.

Bob