no boot up

I have a pan digital nova 7, it will not come on, I don't have the org. power supply, on the case it says 12v 1.5amps center +, I do have a substitute thats 12v 5 amps, with the proper tip + center.
Unless the power supply is propitiatory to pan digital, I thought it would work.
I have tryed to reset it, but still nothing, I have opened the back case and unplugged the battery same thing. If the battery is dead will that stop it from coming on? is there anything else I can try?