yellowed murky plastic

[Tony Duell]

> And cigarette smoke. I've "fixed" several "dim" terminals

Or just general dirt.... See below for an embarassing story from a 
non-smoking environment....

> with the liberal use of 409 (a cleaner). It's amazing how thick
> the gunk can get.

OK, the embarassing stroy. When I was at Bristol, I had a VT102 on my 
bench. The display contrast and brightness were falling off, and it got 
to the point where it was only marginally readable. I got out the 
printset (with my hand-drawn diagram for the later video board..), 
started checking volages. All looked fine. Looked at the waveforms round 
the video amplifier, looked fine. Plenty of beam current too....

After well over an hour of checking signals and getting nowhere, I 
cleaned the screen....

-tony