Older Hp laptops have a common issues of overheating and thus causing the gpu to become dislodged from the logic board. Doing a simple heat reflow and adding a copper shim between the heatsink and the gpu will help tremendously.
Im willing to bet that is your issue, even though you have video out, and some video locally, I think its on its way out. Eventually you will have no display but the computer will turn on, and you may or may not have video out.
If you google "Heat reflow on dv2000" you will find some forums explaining how to do it, and some videos as well. DO NOT USE PENNIES!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
If you need more help let me know, it requires a heat gun, some type of heat shield ( I use aluminum foil), thermal paste, copper shims, and a precision driver set. All in all its not that difficult to do, just kind of a learning experience.