Yes indeed,you should be able to do this,although as you have noticed,there are some subtle differences in the deflection circuits between the two screen sizes.

However,It might be worth trying the "official" test procedure too?

In my own experience,blanket "re-capping"is not often the solution.

There are several "usual suspects"when this problem presents.This was/is a very reliable chassis,and the problem you have is the very sophisticated protection system preventing the set from powering up.

Nick

Thanks Nick - can you believe it took me a month to notice your reply 😂

This certainly helps. I'll probably start with repairing the MX4000, the summer house can wait six months now... The LX6000 chassis is annoying to work on - the plastic frames are very brittle and something keeps breaking all the time. I might even consider finding a donor.

I fixed my MX6000 with similar problems more than 10 years ago and it is still going strong. In that, the final culprit was one of the small transistors driving the BUT12.

Trying the test rig is probably the next step. I tried the test mode with protection circuit disabled, and the set stayed on for a long time without any apparent problems. Might be a tricky one to find.