relay and diode

Even a good diode D601 clearly in parallel of a relay coil will appear bad, can be perfectly healthy with no need to guess-replacing it. It is implemented there to protect the circuit that energizes the relay.

Measure speakers output nodes for direct current before the relay, both channels, zero volume. If there is DC on any, the protection circuit will prevent the relay to connect the speakers to avoid frying them. And by the way check 'speakers-on switch' if there is one.

Ok thanks would that be directly from the stk4211 pinouts.

Probe for DC the output leads from whatever is the final audio output amplifier. An oscilloscope is better.
Print it ! ---> https://www.manualslib.com/manual/1049170/Sony-Ta-Fe370.html