ipod classic flashes apple screen and bleeps.

My ipod classic sometimes is recognized by itunes and sometimes not. It doesn't seem to hold power. It won't turn off when I hold the bottom of the wheel down. Lately it often gets into a cycle of flashing the apple screen and bleeping and continues to do that until it runs out of power. I have restored to factory settings with no change. I supposedly had a new battery put in, but no change. What might fix this?