The problem with the DV9000 is that overheating causes the graphics chip to fail. HP introduced a modification to improve cooling but this does not fully cure the problem. After 12 - 18 mouths use, the main fan and heat-sink become clogged with dust and the heat is not taken away. The only way to alleviate this problem it is to strip down the laptop and physically remove the dust.
You can find guides on how to perform the strip-down on the web and on You Tube, however if you are not technically competent, then it is worth paying a specialist to do this for you.
So, if you have a DV9000 and it is working properly, then you need to take some action every 12 months even if it has been repaired and modified by HP under warranty.