The C53 is expensive to purchase so want to leave that till last!
The negative voltage is showing until it shuts down, then goes back to '0', its an analogue meter and quite sensitive, if there was anything there it would let me know. Im no expert but it seems like its coming on but quickly shutting down.
Is it worth changing the diodes or should I just check them?
I have no idea how to check TR20, how do I do that?
I dont mind changing every componant on the board if I have to, but would like to know where to start............
UPDATE...
Ive just unsoldered one end each out of D 19,20,21,22 and not getting continuity, is it likely they have all failed open?
If i set the meter to measure resistance on the 200M scale I get a reading, does that sound right or have they failed?
Checked R100 and its ok.