The failure to come on is caused by the controller UC3843 (IC801) not
having its startup voltage. This is derived from the chain C843,
C844, R100 and D822. In my case C843 had lost its capacitance.
Eventually, due to the leakage through it the monitor will start up
after a long wait. I don't know yet if this solves the clicking
standby fault, but it very well may be. I fixed it by removing C843
and C844 and replacing it with one of those EMC capacitors. The value
is not very important, should be around 0.5 uF but in my case was 0.15
uF/275 VAC. The display started up happily after this. It has a very
crisp picture, so I'm happy now!

Steven