HP DV9000 no video, part 2.

[David Farber]

A while ago I started this thread about an HP DV9000 laptop that had no
video.
https://tinyurl.com/ndtmko6

The follow up to that story is I sent the board out for repair. Nearly two
months later, I got it back. I reinstalled it and it worked fine....for two
days. Then the video went dark again. I decided the best thing to do was to
order a brand new board and not have to deal with intermittent, old,
connections causing me grief. Now the situation is, as is with many of these
HP boards, how do I keep the processors cool to prevent a reoccurrence of
the problem?

Here are some pictures:
http://webpages.charter.net/mrfixiter/images/Electronics/DV9000/cpu-northbridge.jpg

http://webpages.charter.net/mrfixiter/images/Electronics/DV9000/GPU-shim.jpg

Let's begin with the biggest concern. In the first photo, there is an extra
piece of copper that extends downward toward the motherboard. It's labeled,
"Northbridge 1.5mm gap." That is approximately how much space there is
between the copper and the Northbridge chip when the heat sinks are
installed. On the old motherboard, that gap was filled with a spongy thermal
pad. The consensus is that if there were an uninterrupted piece of copper
between the heat sink and the chip, the cooling would be much more
efficient. By the way, what is that stuff that can be peeled off? Would that
just be regular electrical tape?

Here is a good video showing the orientation of the components.
https://www.youtube.com/watch?v=t9w-khwIj3U
I'm not sure I would stick a penny under the heatsink to fill in the gap but
that's what this particular user did. The other thing I don't understand
from the video is why are shims inserted under the CPU and GPU if they
already come in contact with the heat sink?

In the second photo I linked, you can see the heat sink for the GPU. There
is black tape attached to the heat sink. Does that help dissipate the heat?
Is that there for electrical insulation? Finally, the motherboard came
shipped with a "bonus" copper shim. It's too thin to help with the gap in
the Northbridge chip. Referring back to the video, the user put one shim
under the CPU, and another one under the GPU. I decided to put the one shim
I received under the GPU since that seemed to be the cause of the failure.
What makes more sense to me is to fill in the Northbridge gap with copper
shims (is it ok to stack them if I can't measure the exact thickness before
I buy them?) and leave the CPU and GPU as is. What do you think about this?

Thanks for your replies.
--
David Farber
Los Osos, CA

[David Farber]

Here is a follow up to what has happened since I posted this in October:

The new board which I ordered powered up but wouldn't POST or light up the
monitor. I returned it and the eBay seller sent me a replacement and was
kind enough to reimburse me for shipping.

The replacement board arrived. I plugged it in and all seemed good. I was
quite happy. Then I noticed that the Windows battery charging icon was
acting irregularly. It would show 100% for a second or two and then drop
down to a much lower number. I knew the battery was old and didn't have much
juice left so I ordered a new battery from Amazon and it arrived in less
than a week. I tried it out and it was the same thing. However I now noticed
that not only was the Windows charge remaining icon still reading
erratically, the battery was not charging. Did I have another bad battery? I
called a local retail store that specializes in all types of batteries. They
had a replacement battery for this laptop. I asked the manager if I could
try it first before buying it because I wasn't absolutely sure the one I had
was defective. He said that fine with him. I drove to the store, plugged in
the laptop on the display counter, and tried the new battery. It read about
55% charge remaining. After about 15 minutes, the charge remaining indicator
hadn't budged. It stayed at 55%. I then unplugged the power adapter and
watched the charge remaining indicator countdown to 50%, then 45%, and so
on. I turned off the laptop, plugged the adapter back in, and waited to see
if it would charge. By the way, when the battery was installed and the power
adapter was plugged in, the charging light on the laptop always came on. I
browsed around the store for about 15 minutes and then powered the laptop
back on to see if there was any charging happening. The result was it hadn't
charged at all. I knew then that the motherboard's charging circuit was
defective. One used battery and two new batteries, (different brands) were
not charging. To make sure the batteries I had were good, I installed the
original motherboard with the no video display into the laptop and that did
charge the batteries. I contacted the eBay seller and he wasn't thrilled to
hear about my report. But he sent me a replacement after I returned the
second one.

The third one arrived and of course it was as bad as the first one I
received. It didn't POST or light up the monitor. I now began to question
the seller about how could I get three, brand new, bad motherboards? He said
he had had trouble with one of his suppliers but I was the only buyer that
had recently complained. I still wanted to get a replacement board as long
as it was NEW (I was beginning to have my doubts if any of these
motherboards were new). The seller said he'd get back to me but he didn't.
Time was passing by. He had my returned motherboard AND my money. I then
emailed him a week later asking for a refund but I received an email from
him that a new board had already been shipped to me. I waited for tracking
info and never received it. And of course I didn't receive the 4th
replacement motherboard either. That's the last I heard from the seller. I
filed a claim with PayPal because eBay will only accept claims after 30
days. This had been going on for about 3 months. I had to call PayPal
several times to make sure they were following up. Each time I was on hold
for about an hour. Finally, my money was refunded to me but not the full
amount. PayPal deducted the shipping reimbursement the seller had given me
for my return shipping charges for the first motherboard.

On a brighter note, after getting tired of waiting for the fourth board to
arrive, I used my economical eBay hot-air rework station and attempted to
get the video on the original board working again. I really had nothing to
lose. I used the largest diameter attachment that came with the kit, set the
temp to around 350 degrees F, and then just kept the air moving around the
area of the GPU chip and the peripheral components. I maybe did this for
about 5 or 10 minutes, then turned it off and let it cool. I reassembled the
board, plugged it in, and powered it up. It worked perfectly and has been
working now for more than a month.

[Genesys]

Don't buy eBay motherboards for OEM equipment (boards for DIY PC builds have been fine for me so far). Nearly all "new" OEM motherboards in my experience are just used pulls from (then-)working units.

From ones I've bought, they always seem to have something wrong with them. My DOAs generally just didn't POST, but had one with a bad SATA controller. In other cases, they just weren't in the condition listed (typically listed as new, when "used", "seller refurbished", or in one case "as-is/for parts or repair" were more appropriate).

[David Farber]

I didn't realize that motherboard sellers took such liberties were their
product descriptions. I suppose they have product to move and do what's
necessary. It is also *very* difficult to get any support from eBay or
PayPal when trying or to prove an item isn't "as described." I won my PayPal
dispute because I saved the tracking numbers for all of the returned boards
and argued that the seller didn't have any plans for sending me another
replacement.

Thanks for your reply.