If after thoroughly washing the kinescope base with thinner, checking the welds, checking the voltages and filters, and you still have to hit the kinescope, the kinescope is definitely defective. in the network there are testers to "rejuvenate". What we do, is to look for another even if it is another brand and give the customer the option.- Well, there are no new kinescopes, and getting a used one does not know how long it will last. regards.
solved very well the plaquita that is behind the kinescope especially the three transistors amplifiers of color maybe they are desoldered and welded any point that you find with cold welding.
It is possible that the integrated jungle is also with false pins, check if it is possible to weld the pins again.