After a week of annoying fiddly and complicated amplifier faults, I was rewarded with sweet little simple job.
A nice little Alamo, USA made amplifier. Single ended with a 6V6G, pre amp valve is a 6SL7 and 5Y3G converting undulating angry pixies into one big flat one. The mains fuse was blown and the power switch was stuck in the off position. No obvious faults found, so the switch was replaced, along with the fuse. The mains fuse had shattered, so whatever the cause that was quite basic. The snubber capdensor across the mains switch was slightly leaky, so replaced it with a correct X2 type. The HT reservoir capacitors had been previously changed. The grid coupling capdensor was fine. Being a USA made amp, it was labelled up as 110V working. Checked with the customer and he advised a replacement mains transformer has been fitted some time ago. With current limiting in place, powered her up and all worked really well. The cabinet is fitted with a large Jenson loudspeaker and considering it is driven by one little 6V6G valve, it packed a punch like a 50 Watt Marshall stack. Nice.