Swapping CRT
 

I have a set with a bad board, and a set with a bad CRT. They use the same CRT part number. What does swapping a CRT entail? I’ve never done it.

Depends on the age & brand. Can be super easy on new sets
especially if it uses the same yoke. You can do those in 5 mn.
Older ones take more time & you usually have to do a
complete set-up.

73 Zeno:smoke:
LFOD !

The sets are almost identical. First one is 1994, other is 1996. Panasonic CT-20S11S and CT-20G11U. I have the service manuals for both.

Workflow should probably be: remove PCBs from cabinet and make sure CRT is disconnected from PCBs on both sets, flip sets on their face on towel or carpet to prevent CRT face scratches, make sure no wires tether the CRT to the cabinet, remove ~4 bolts that fasten the screen to the face to the cabinet, remove bad CRT first then remove and transfer good CRT. After that, it is reassembly and making sure you have a yoke that will connect to the good board.

I've never done this with an SS set or done a neck hardware adjustment on an inline gun CRT, but I've scrapped plenty of SS sets. Workflow is similar to the old tube sets which I have done many swaps on.

Things to watch out for are CRTs with different physical dimensions that look the same and tubes with different electrical specs.

Should I discharge the CRT?

If it has been off for over a day or two you probably don't need to. Many SS sets have HV bleeders and don't hold a charge after a few mins but some don't. It is not like the charge its self will harm you (though what your reflexes do as a result might). Your call really.

Look up the yoke part ##'s if the same leave the yoke
& magnet assy on the neck. That will speed things up & you
will only have to adjust the grey scale, focus & G-2 at most.

73 Zeno:smoke:
LFOD !

RCA sometimes glued the yoke to the CRT, but they usually had a sticker saying that that was done. RCA also used a magnetic strip wrapped around the CRT neck, between the yoke and the CRT neck pins. At the factory, the convergence is adjusted by a machine that, once convergence is good, will "record" the required magnetic polarity and strength into this strip, like if it was a piece of tape from say a cassette. If the yoke part numbers are the same, I'd just keep the yoke, CRT and convergence adjustments together when you transplant the CRT into the other set.