Fixing an HP dv9000 (dv9723ca) with No Video and Audio (In Surrey)
When I picked up this HP Pavillion dv9000 on 31Mar2012, it was described as "no longer works. The monitor doesn't turn on. One of its hinges is broken and we had the ram and hard drives taken out."
I inspected this dv9000, the right hinge was broken. Touch pad button had paint scratched. From the parts that I kept from another dv9000, I salvaged the hing and touch pad to fix this hp dv9000. For no video, I checked the fan and the video chip. Fan had some dust which might be the cause of no video due to GPU overheated.
The video chip did not have an sign of reflow attempt. I removed the red epoxy around the chip so that I could inject soldering flux to it. I performed the video chip reflow on 1 April 2012. The reflow was successful. Video is back. I installed 2 GB RAM and a 160GB hard drive on it which has an HP recovery partition inside. It ran except no sound and there was a pop up message "No Audio Output Device is Installed" on the speaker icon at the bottom. I tested all three audio drivers from the HP website on the dv92723ca model. All did not work.
In 5 months, I was thinking and inspecting the motherboard for any possible issue. On 22Sep2012, the dv9000 still had video and wireless except audio. Without any solution, I attempted another reflow but still had no luck to get back the audio.
My next attempt was to replace the audio chip. I found the system diagram and located the audio chip CX20561-12Z which is very small with many legs. I ordered a new one and used hot air rework station to remove the old chip and put in the new one. When I booted up the laptop, the power panel had blue lights on the indicators except the speaker which was in red. When I pressed on the chip, the red speaker indicator turned to blue. I tried to add more solder which had shorted the circuit inside the chip. When I rebooted the dv9000, it had no video. I did another reflow. It happened twice. I suspected that the damaged audio chip caused overheating to the GPU.
To try again, I ordered another new audio chip and solder paste that I could solder the chip properly. I soldered it but still no audio.
I finally order a new motherboard. It arrived on early March. I assembled the motherboard and installed the Windows Vista from recovery partition. It is working fine.
It was picked by an African student living in Surrey. He would return to Africa in Summer. We met on 16May2013 at 29th Ave Skytrain station. I discounted the price for student.