Philco 50-T1403 with focus problem

[bgadow]

I have a 12" RCA (2T51?) with this problem. It just uses a permanent magnet for focus. First I found that the travel of the magnet is very limited-after a lube job and with some help I can get it to go through the full travel. From looking at other sets this looks like a common problem. But, even after getting that figured out the focus still won't improve. I tried swapping magnet assemblies from another set (I do have some spares) but still no luck; just holding a strong magnet up to the neck didn't seem to change the focus either. I had guessed, in my case, that I had either B+ problems or a defect in the crt. I am going to follow this thread close. I will have to look for a possible DC restoration issue, I guess; without reading the ARF thread, wouuld it effect this set which only uses the perm. magnet?

Strange that the test tube would work. It seems like that would eliminate everything but the crt but it doesn't...