one touch problem!!

can anyone with a deluxe home kit pls advise.

my unit is a little old and i havent used it in about 4 yrs. it also needs replacement tips…i connected it to a battery and there was no noise at all, i seem to recall if u touched the little silver bit on the unit with the stylist tip, then it would make a sound…am i right in thinking this??
anyway as i have no tips i cant do this and i just want to have some idea as to whether my unit is knackered. i did take it apart and the little circuit board is still intact. i just dont want to waste money buying new tips.

so, does the unit make a noise when connected?

thanks in advance