21fbp22 front lens cleaning
 

hey guys anyone familiar with the 21fbp22 lens, is this lens held on with a rubber band type of thing that goes all the way around the edge of the tube and is there any pva or oil type material between the surfaces or does it just have an air gap between the tube and lens? it has a slight cloudy area in some spots, i figured i could separate the two and use windex to clean it up. looking at the front close it looks as if it has a gap between the two. befor taking it out should i make marks to put it back in its exact place the way it came out being it is a round tube.

If there is no green ring on the viewable face then it probably is not a bonded face mask type (if there is are spots that look like water drops near center then it is almost certanly not a bonded type). I can not remember the number, but back in the fall I removed and cleaned the safety glass from a non-bonded roundy color crt. It went like this, I removed the chassis and left the the CRT and left all its neck hardware in place, then I (with the set on its face) removed the four bolts that hold the CRT, and made a mental note of every things position, then removed the tube. To get the safety glass off I had to unscrew the metal mount that encircles the face of the tube and remove it, then I was able to lift the CRT off (it was on its face) of the mask. Inside was a substance like vaseline or soft wax that was a minor nusence to clean off (because there was a ton of it), not sure what its function was. After thouroughly cleaning the safety glass inside and out as well as cleaning the face of the CRT I reassembled the glass, CRT, and mount; I placed the CRT in the cabinet of the set in about the same position. I then lightly tightend the bolts and fliped the set upright to check if the tube was centered. It was not so I fliped it down, loosened the bolts, slid the tube the amount I thought it was off by, tightend again, checked and repeated untill I was happy.
My tube was not properly centered to begin with so I was not too concearned with noteing the EXACT original position. If yours is centered then you probably will want to note the exact position it was in.

On reassembly be carefull that dirt or hair does not get between the glass and the crt (a body hair snuck in durring reassembly, and I did not realize untill it was back in the cabinet, luckly it droped out of sight below the mask other wise I'd of had to dismantle it again to remove it).

Mine did have a black rubber ring around the safety glass.

Hope this helps.

Tom C.

And clean the o-ring too! They will get oiley/drippy/sticky. Other than mentioned, it should be a pretty straightforward process.

thanks guys...

91% rubbing alcohol is best for cleaning the sticky goo off of the gasket.