Skype_man wrote:
Flyback was arcing badly, replaced, works, & looks perfect,
but momentarily shuts off, & right back on, even before you
can look back at the set. may work for hours, or happen twice
in a half hour. Unplugged the customer controls on top of the set,
to make sure the "tact" switches aren't "leaky". Anything common
here? Nothing on the Thomson B2B website. Sky.

Google groups search here for the ctc203 chassis.
Find the base driver coil that it seems you missed which is very common.