If nothing at all happens, that sounds like the power supply - transformers don't last for ever, if you can hear a mains hum, then at least the primary is there - there could well be several secondaries, if that's the case then something should wake up. A lot of 'old' stuff can have internal fuses - usually in a glass tube, so you can see if they've blown. They can be weird sizes and ratings, if one's gone.
If you go by Collectable Records on Wolverhampton Road and there's a bike locked to the blue steel gate, then Steve may have a suggestion in the right direction.
Electronic repairs for consumers is rather a last-century service these days, unfortunately...
You could also ask in Pickup's - they can only say 'No'.