Magnavox CD4756 (T989 chassis) dark bands down left edge

[old_tv_nut]

If you have replaced all the caps in the H sweep circuit it must be something else. I don't know, check caps in horizontal oscillator and amp sections?

Cracked circuit/solder traces taking one of the safety caps out of the circuit? Can you check connectivity from the horizontal output collector to the lead of each safety cap?

I was going to suggest looking for a capacitor mounted on the yoke, but I don't see one on the schematic.