HT asked ... Radio code Philips 22RC200/35?    |    Roberta asked ... DW5080?    |    Dave asked ... Toilet Push Button not flushing properly?    |    Dave asked ... Repair kettle lid?    |    Sandy asked ... Replace vertical gear on Singer Fashion Mate 252?    |    Click here to ask your question

how to make my vienna wall clock chime on half hour?

my double vienna wall clock will not strike one on the half hour it chimes any thing fron one to twelve
it does strike the hour o.k.
any help would be appreciated
thanks
mrs pat smith, January 2011