I assume loss of pix means "went black". Almost always thats loss of HV.
Easy first. There are 4 tubes that will cause it. Hoz osc, hoz output,
damper, & HV rect. I have never seen a HV rect go int. so leave that out.
With the set running lightly tap the tubes & see what happens.
This is usually better than a tube tester for this type fault. You can
also do it on a checker to smoke out an int tube but having the TV raster
works BEST !
Freeze mist was mentioned also. A real life saver sometimes. Best way to
use it is spray it on a Q-tip & touch it to suspect parts one at a time.
It will almost always be a cap.
BUT keep in mind if you chill down some caps to much they will drift
out of tolerance & act up but still be good.
good luck
73 Zeno
LFOD !