A samsung galaxy player 3.6 that wont turn on

The charger has a function that restores the battery operation parameters by discharging then charging the battery a number of times. Refer to charging instructions in the pack but I think the cycle is a 3 hourly one, time to charge from a full discharge. If the charger thinks the battery is dead then it will try to recover the battery using this process. You may have left the charger on long enough to charge then also discharge the battery.
Start again and charge for the time in the instructions ONLY, if you are not sure of the time try it for an hour, then without disconnecting the charger turn the unit on and take particular note of any screen messages, if any.
You should be able to continue as normal now, but still be aware of the time you are leaving the charger connected for, as it may take some time before it returns to normal operation and stops trying to recover what it thinks is a dead battery.