Sony CDX CA750

Hi guys,

had this unit for a few years connected to a CDX656 changer. the radio
recently has started to drift from the tuned channel and then just hisses
until turned off and then for a short while it works again. everything else
works ok, it was suggested that the car aerial could be at fault, but i have
just got a new ignis and it still does it.

anyone know if its a minor repair or scrap and replace.

thanks in advance

sean