Having been rather lucky over the years with CRT karma, it changed. That's the gamble we take.
Within the last few years, picked up several sets at prices that preclude a CRT check. Two early 50's and very clean Westinghouse floor models had air-infiltrated and guns lit up purple when tested. One set was 16" with matching stand and went to live as a stage prop at a university, the other was an early photocell-equipped automatic brightness and 1953, the last year Westy's were made in Sunbury. This one was absolutely worth a new 21FP4, which I got from another VK'er, who got it from Moyers.
The latest was a beautiful RCA CTC16X Carlstadt, the original 21FJP22 presented as an easy cataract, so I waited to get it home. Plugging the tester onto the loose and cracked base, expecting an equally sleepy trio of cathodes, the green never came up.
The green heater was not lit and upon closer inspection the filament was totally gone. This explains why the set was sitting but it had a replacement flyback
