Hi,
You could try a factory reset - Menu, 4, 7, 2, 5,
If the chassis is type 17MB60 or 17MB62
a common problem are the four SMD capacitors
C1075, C1076, C1077, C1078 (Pins 3 ,4 ,11 , 12 of the Audio Power Amp I.C.).
Change from 470nf to 1uf 6.3v (they are situated near to I.C. U168).
Regards