G1 short in a 21FBP22

[IsthmusTV]

Hi all,

I have a 21FBP21 that tests weak, but may wake up (it's a grade B rebuild). The green gun had what appeared to be a fairly high resistance G1 short. I used the "remove G1 short" function on my Sencore CR-70 several times, and once I did see a bright flash from the neck which the manual says is the short being "blown away." But each time I would retest, it still indicated a short. The short gets worse (lower resistance) the longer it runs. I verified the short on a second CRT tester (a CR-31A).

The CR-70 manual has a procedure for removing stubborn G1 shorts. They have you disconnect G2 and use the "manual restore 2" function for 20 seconds and then quickly switch to "remove G1 short" and blast it there. I did this twice, and the short remains. However, now the green gun tests excellent for cutoff and emission. Could it possibly be usable like this? I thought there would be no cutoff control with a G1 short. I assume that the emissions went way up because of the restore function.

Any other G1 short removal tricks to try or is this thing toast?

Thanks,

Clark