[Arran]

The audio circuitry is independent from the IF cans or the front end, but defective coils in either section will cause the set not to play even if the capacitors are changed. Fortunately you can test those coils for continuity with an ohm meter. An IF coil should have a minimum of four leads, some have five, I would open up the suspected can and investigate what's going on before going further, you may need to find a replacement if it is not repairable. If the audio section is work then placing a screwdriver blade on the center lug of the volume control should result in a loud roar coming out of the speaker.
Regards
Arran