If your shaver works but will not longer hold a charge as long as it should, the batteries need to be replaced. If the shaver is dead and the green indicator no longer illuminates when plugged in, you have waited too long and the circuit board is now damaged and can not be repaired.
For battery replacement, see shaveroutlet.com at the link below
Professional Battery Replacement for Most Models
The battery may not be any good, even though the lights go on they only require a tiny amount of power, the motor on the other hand requires a lot of power, and so it will not run. Pull the razor apart and test the motor with an external battery.