Back in the good old days, people got their information by staring into particle accelerators that could implode at any moment, and we liked it that way, by gum! To protect against disaster, CRT monitors were equipped with a safety screen laminated to the front of the tube. Decades of use often resulted in degradation of the glue used to hold the safety glass on, leading to the dread disease of “CRT cataracts.”
Luckily for aficionados of vintage terminals, [John Sutley] has come up with a cure for CRT cataracts. The video below shows the straightforward but still somewhat fussy process from start to finish. You’ll want to follow [John]’s advice on discharging the high-voltage flyback section of any stored charge; we speak from painful experience on this. With the CRT removed from the case, removing the safety screen is as simple as melting the glue with a hot air gun and applying gentle leverage with a putty knife. We’d think a plastic tool would be less likely to scratch the glass, but [John] managed to get them apart without incident. Acetone and elbow grease cleaned off the old glue, and the restored CRT looks great when reassembled.
With its cataracts cured, [John] says his next step is to restore the wonky keyboard on his Lear Siegler ADM-3A terminal. Perhaps he should look over this VT220 keyboard repair for ideas.