What component failure would cause sync issues?

[Nipedley]

Thanks grant, I have a crap load of replacement parts in the mail (damn postage strikes!) Once they arrive, I can replace the transistors on the 'blue' chassis and fully re-cap it, and at the same time then I'll go through the check list for the sync chassis.

Everything I've ordered before, next day delivery. Been waiting a week now because of royal mail!

[Nipedley]

Right after 2 deliveries each taking well over a week of the wrong component I finally caved in and swapped over the BF859 from the 'sync' chassis and huzzah the blue problem is gone, it now looks great. After some extensive play-testing () I then discovered it has a horrific static sound, almost like it's going to explode. But the picture looks absolutely fine. Am I just worrying too much or is something amiss here?

This is with the back of the cabinet off, so maybe that's why the sound is so prominent but I wouldn't like to finish it off and stick it in the corner only for another component to go next week or something.

[Nipedley]

Just thought I'd ask, while working on the 'sync' chassis some more earlier (I was bored) I noticed that the mains smoothing cap was of the wrong value, 330uF instead of 470uF. It had been replaced by another tech, is that alright or would that potentially cause problems - even the sync problems?

Following the sync signal throughout the entire board and replacing every dodgy component along the way as a last measure