Ken wrote:
David Farber wrote:
This HP DV9000 boots up fine but there is no display video. I did
some checking and found out this is a very common problem.
http://www.pointoflaw.com/archives/2...vidia-clas.php The
GPU overheats and then the video stops functioning. I disassembled
it and found the heat sink vents clogged with dust. I used my new,
economical, 852D rework station to try and reflow the solder on the
GPU though I don't think it got hot enough to melt the solder. I
should have tested the external video before disassembling the
entire thing but now with just the power adapter and RAM plugged in,
the external video is working but the laptop screen flashes dimly
once and that's it. My question is, since the external video is
working, (it displays "No OS found,") does that mean the GPU is
working fine and there is a problem with the laptop screen? Before
disassembling it I tried using the special function key to switch
the display output to the external monitor without the external
monitor plugged in to see if it had inadvertently been switched to
the external monitor only setting. That didn't work but now I'm
wondering if with all the key pressing when there was no video,
perhaps I left it in the state where it's now switched to external
video only. In the interim, the CMOS battery was removed and I was
wondering if that would reset the video to enable the laptop
display. Let me summarize.

1. Unit came on. You could hear the Windows logon wav file. No
display on screen.
2. Disassembled unit. Cleaned fan and heat sinks. Used rework
station in attempt to reflow solder to GPU.
3. Reconnected the RAM and power supply with the motherboard
attached to the case with a couple of screws.
4. Powered on, no laptop video but video works to external monitor.
5. Is the GPU good?
6. How to proceed next?

Thanks for your reply.

I dealt with the same model computer over the Christmas holiday. It
is hard for me to imagine the video chip being a problem if the
external video works. That being said, you are correct about MANY
such computers having a video problem. I did the blow torch/ shield
from the heat method, and the computer worked for about a day. Long
enough to take all the data off the hard drive for the owner.

To tell you the truth, I would not put too much labor into this model
computer. Especially with it's history. You could be making a career
choice.

Hi Ken,

For $80 I can send the motherboard in to have the GPU reflowed and have a
modified heat sink installed to keep it from overheating again. It comes
with a 60 day warranty. The gentleman that fixes it says he's had a very
high success rate and if he can't fix it, there's no charge and free return
shipping. I'm curious enough to see if that will fix it for good. If this
all works out, I'll let you know.

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