Bush TR 82C repair advice wanted

[AlanBeckett]

Also, some readings would depend on the exact battery voltage. OK, they might have powered the set from a power supply set to 9V, but how accurately could they have set the voltage? And how close to 9V is your battery?

Well said. I once spent half a day chasing a 'Fault' on a piece of Battery Powered gear I was designing. It eventually dawned on me that I was running it on a gradually fading Battery.
I can't type what I said about myself but it started with Dumb.

Alan