Thanks, I'll look into that. I think
this is the circuit diagram for my TV?
I guess I'll need to order some parts for this before I can get any further, which is unfortunate. There also must be some other big fault because one thing I forgot to mention is that I had to replace a blown fuse right at the start. Something must be broken to have caused the fuse to blow...
Other than a zener diode, what components would be a good idea to buy so that they are on hand for whatever may crop up in the rest of this repair project? Capacitors, resistors, certain types of transistor?