ITT CVC5 CHASSIS

There’s a loud crack from within this set shortly after it’s
switched on. There’s no flash on the screen however, while
the set continues to operate normally for as long as it’s
switched on. The crack does not occur if the set is switched
off and then on again within two -three hours, but if left
overnight then on switching on this “capacitor discharge”
type sound occurs soon after.
The discharge is probably occurring from an e.h.t. point,
and we suggest cleaning around the e.h.t. connector on the
top of the tube. Then spray this with “damp start” or some
other silicone compound. If necessary remove the line
output stage screen to see whether the discharge can be
spotted somewhere around the tripler or the line output
transformer.