Audio Systems: 1993 Lincoln JBL radio problems, lincoln town car, salvage yard

Question
I have a 1993 Lincoln Town Car with a JBL sound
system in it.
The radio has quit producing any sound.
It still comes on, raises the antenna, scans the channels, but no sound.
Recently it has produced sound but not for very long.
I have a suspicion it is an amplifier, but don't know which one.
Looking in from the trunk,on the right side I see a black amplifier? with the JBL logo on it.
On the left side behind a cover there is a metal box, I don't know if this is an amplifier or not.

I plugged another radio in from a salvage yard, but it worked the same as my radio did.

What should I do?

Gale

Answer
and if you buy 2 more radios from the same place the result will be the same and no it is not the amplifier or speakers it is the radio 2 bad radios you can get 10 radios and 9 will give you the same

this radios sufer of that the jbl radio have a problem with the capacitors from 1988to 1995  the best thing is to buy a rebuild radio
you can find one here but since they are the only company that rebuild them  they are always out so is best to call first
http://www.partydown.com/items/item359.htm