I had a bit of time to spare today so I thought I would fit the parts to the Marconi. I fitted the 12 volt socket replaced the on off volume control and knob.
The knob on my set looks like it came from a transistor radio it originally came from a pot with a splined shaft. Someone had sawed slots in it to fit the flat on the control on the TV.
Once the set was back together and working I decided to dismantle the original control to see what damage had been done.
The switch contacts are blown to bits, the track that formed part of the switch was also fairly blasted. no wonder the control crunched and crackled!
Some pictures...
Rich.