CTC197 notorious for bad flyback. I put a meter on the collector of the horiz output. Read AC voltage at turn on, then put a HV probe on the anode wire and read the HV at turn on. A good working set has about
300vac rms on the output, 30kv on the anode. Of course you need a good meter with min/max setting to really do this. The flyback if bad will load down AC on the collector, but the basic readings will still be usable. For example if you read 150vac at turn on, but only 2kv on your anode, you know the flyback is bad or the yoke is bad or the CRT has no vacuum or you have a shorted diode ect, off the flyback. Check the diodes, unplug the yoke and the CRT board and see if HV increases. If not, bad flyback. CTC197 not one of the better sets RCA has made. Flyback probably on factory back order, always is.