my grandaughter clock stopped chiming :(?

i have recently bought a 1931 grandaughter clock, when i set her up at home she worked perfect for the first hour, then she would only dong on the hour every hour (just one dong) now she won't even do that! can anyone tell me what might have happened and hopefully give me a simple solution. She is supposed to do Westminster chimes on the hour and part westminster chimes every 15 mins..

looking forward to replies :)