Gentlepeople,
I have a VR201 (DEC Pro b/w monitor). It's been stored for a while.
I just noticed that the faceplate has spots on it which don't clean off.
More precisely, it looks like they are spots (bubbles?) *inside* the
faceplate coating material.
The faceplates on these CRTs are made of 2 layers of glass bonded
together, a bit like a laminated windscreen (windshield?). This is part
of the implosion protection fo the CRT, if the glass breaks it will not
fly everywhere.
The bubbles seem to be due to the adhesive layer between the 2 bits of
glass breaking down.
There have been several methods described for fixing this. You basically
have to separate the 2 layers and clean off the old adhesive. Some peopel
the say you use the CRT as it is, without refitting the outer glass
panel. This worries me -- a lot. An imploding CRT is not fun if you're
sat in front of it.
I susepct you could stick the outer layer back in place with optical
adhesive, the sort used for fixing lens elements together. But I have
not tried it.
FWIW, all teh CRT manufacturers whose data sheets I have read tell you
under no circumstances to attempt to remove the faceplate./ OK, they are
probably coverign their own backsides, adn they want to sell new CRTs
anyhow, but it can't be a risk-free procedure.
Any suggestions for how to treat this?
Depnds how original you want to be.
If you don't mind using a different monitor., it's not hard to wire up a
cable with a DA15 socket (I think) on one end, and a 4p4c socket (for the
keyboard) and RCA phono socket (or whatever) for a composite video
monitor on the other. It is a normal RS170 TV-rate monitor.
If oyu can find a suitable mono CRT spare (old portable TVs used to be a
good source, but I suspect thsoe are as rare as VR201s now), I'd replace
the CRT. Just about any 12" 90 degree mono CRT can be got to work here.
Or you coudl try to separate the facpalte and rebond it. But take great
care if you do.
-tony