[indigo.girl]

I started to trouble-shoot before your posts Julie and Lawrence....this is what I found...

To start with the lamp limiter bulb didn't glow at all suggesting no current was getting through to the radio at all. So I checked the on/off switch that's part of the volume pot. I could measure 85V AC across the L and N going into the switch but zero volts coming out no matter how I turned the dial. So I presume that switch is broken.

I decided then to bypass the switch and so I connected the switch outputs to the mains input. Still nothing but the lamp limiter bulb does faintly glow now. There are lots of wires connected into the transformer that I can't identify but there are two output wires than connect directly to a small bulb that illuminates the wavelength selector screen. I measured across here and there is zero voltage across these outputs which at first suggested to me that there was something wrong with the transformer since I was not getting an output. However, I can now see that all three valves are beginning to glow. (AZ31 the rectifier is not) so something must be getting through.

EDIT: Upon further testing I can now measure 4V AC across the screen bulbs - no glow but I'm wondering if thats because 4V AC is too low and perhaps the bulbs may work when I remove the lamp limiter (Not going to do that yet until I'm sure its OK to do so).