Hp ipaq seems dead
Without know exactly what already you tried to powered it on, I can only especulate on all the possible reasons, so let go one by one throuh them and their possible solutions:
1. The RX3000 Ipaq family has a known mechanical issue on the switch that senses when the back cover lid is properly closed.
When the switch is nor properly depressed, the PDA won't charge the battery if plugged on the cradle or to the USB sync cable, or won't turn on.
Remove the back cover lid and the battery, put them back again. Check the cover lid is placed flush and that there is not any gap between the cover and the PDA body.
Try again in power it on and/or charge the battery, confirming the orange LED light is turning on.
2. Either the cradle/USB sync cable or the AC wall adapter are defective.
The PDA won't power on if the battery is not charged to the minimum voltage for it. If the AC wall adapter or the cable/Cradle are defective, won't power on.
Put to charge the battery and confirm the orange LED light is turning on. If so, the you can discard that the cradle/USB cable or AC wall adapter are defective.
It the orange LED light won't turn on, it may be either one of these three parts that are defective, or that the back cover lid is not properly closed.
3. The battery dried out. If the battery is defective or won't accept charge, the pda won't power on.
To discard a defective battery, put the PDA to charge it, and it will power on when plugged to the USB cable or to the charger, and check in the settings screen, on the power icon, if the battery is charging.
If the back cover lid is properly placed, and the PDA won't power on when plugged to the USB cable or AC wall adapter, then the battery is not the problem.
4. Discarding that the battery or the USB cable or cradle or the back cover lid are the problem for this problem, the only option that is left is that the main board is defective.
Such failure on the mainboard could be caused for several reasons (moisture or humidity or water damage, or a electronic component that is worn out, or a integrated circuit that is shorted, etc) but it can be only verified and confirmed by an electronics technician.
You have the option of send it to be repaired, or try it yourself, which will require to buy a PDA with working mainboard (or the mainboard alone) and swap the parts. It requires a minimum of technical skills to do it.