[thejazzageuk]

Thanks Techman and PJL. I think replacing the reservoir as you suggest is a good idea- I will order 4 of the ones indicated by Techman today.

I have removed the rectifier and checked out the heaters, initially they were very different, and the brighter one was a bit uneven with some elements brighter than others. However after a few cycles they seem much more even and a bit closer in brightness- you can still see one is brighter though. I checked the heater voltages- both are showing 3.8v.