On Friday, June 11, 2021 at 10:10:13 PM UTC-4, wrote:
I bought an HP 2621a CRT computer terminal in 1980. But about fifteen years
ago the screen got black spots like mildew. But it ain't mildew. Apparently
the glue holding a plastic sheet over the glass is decaying. I looked online
and found you have to peal that plastic off and remove the glue. I do have a
Zerox (ok, it was Savin then) copy of the service manual, but it says nothing
about this. Yeah, it's nostalgia and prolly not worth the effort. But would
appreciate any tips from anyone who has done anything like this before.



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The CRT is considered a single replaceable component. Removing the bonded safety glass is very dangerous and something no manufacturer would recommend. John Robertson's advice to wear armored clothing and eye protection is a good one if you want to attempt to remove the safety glass. I've used a heat gun and piano wire stretched between a couple of pieces of wood dowel to slice the glue to remove the cataract safety glass, but both the tube and safety glass were indeed glass. If that's some sort of plastic on the HP, I don't know if the same procedure would work.