On both sets check:
1) the G-2 is not too high. Should be apx 450 VDC. at CRT pin
2) on the CRT board there are 3 identical resistors ( apx 18K 2 watt)
Where they join be sure you have apx 200 VDC.
3) if you turn down the bright, contrast & color level you should be able to extinguish or nearly so the pix. Turning back up the brite & contrast should
show a constant B&W pix as you go up. If it changes color as you go it may
be the CRT.
good luck.
73 Zeno
LFOD !