Well spotted!!
That is a tantalum capacitor and it is in the audio output circuit. It is very likely your problem.
It is a filter on the negative supply voltage line with its mate on the positive line, C46? I would probably replace both.
It could be replaced with an electrolytic capacitor in this application if you have trouble finding a suitable tantalum replacement.
It will probably be listed in the parts list but it is a 1mfd probably at 35 volts?