27 May
2004
27 May
'04
3:58 p.m.
Hi folks,
I've had a Lear Siegler ADM 3A terminal in storage (a closet) for a number of years,
and recently went to pull it out.
Much to my disappointment, the CRT now has some problems (_physical_ problems, not
electronic).
When I originally stored it (about 4 years ago), all was well. But now there are bunch of
"spots" peppering the outer perimeter of the front of the CRT. These spots are
NOT on the surface of the CRT (i.e., it is not a "bubbling" sort of phenomenon),
but rather behind the outer glass.
Here are some pictures: (approx. 35K each)
http://home.san.rr.com/instep/adm3a-crt.jpg
http://home.san.rr.com/instep/adm3a-crt1.jpg
When I power the terminal up and type some characters, they are all perfectly readable
when located away from these spots (i.e., towards the center of the screen). But if the
characters are positioned behind these spots, it is as blurry as hell.
1) What's happened to my CRT? Is this symptomatic of a slow air leak? Or is this mold?
(it sure looks like it! :-)
2) Can the CRT be fixed/repaired? (my guess is no)
3) If it (the CRT) can't be fixed, does anyone know a source for a new (or used) one?
(It is a "Ball Brothers Inc." CRT)
Kind regards,
Eric
28 May
28 May
12:26 a.m.
[...] Lear Siegler ADM 3A [...]
When I originally stored it (about 4 years ago), all
was well. But
now there are bunch of "spots" peppering the outer perimeter of the
front of the CRT. These spots are NOT on the surface of the CRT
(i.e., it is not a "bubbling" sort of phenomenon), but rather behind
the outer glass.
Based on the picture, I would guess this is the problem that's been
discussed on-list in the past, where something glued to the front of
the CRT develops problems. But that's just a guess, and a rather
uninformed one at that; I'll let those who actually know the problem
speak to that.
1) What's happened to my CRT? Is this symptomatic
of a slow air
leak?
No; that is so unlikely that I wouldn't even consider it, and it
doesn't fit the symptoms anyway. The vacuum inside a CRT has to be a
pretty hard vacuum, and even the slowest ordinary leak will completely
ruin it in no time flat. In principle it may be possible to have a
leak slow enough that it still mostly works after some years - but it
wouldn't affect some areas of the screen and not others; gas in the
tube will affect the whole screen, because it will interfere with
electron flight everywhere.
2) Can the CRT be fixed/repaired? (my guess is no)
If it's the problem I refer to above, it can be fixed, but it's not
trivial. Again, I'll let people familiar with the problem speak, if
they think it might be what's wrong with your 3A.
/~\ The ASCII der Mouse
\ / Ribbon Campaign
X Against HTML mouse(a)rodents.montreal.qc.ca
/ \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
3:29 p.m.
Based on the picture, I would guess this is the
problem that's been discussed on-list in the past,
where something glued to the front of the CRT develops
problems. ...
dOh!
You are certainly correct, der Mouse. This problem was discussed on-list
previously. My bad.
For those interested, search the archives for "hp 262x terminal help sought".
Kind regards,
Eric
7590
days inactive
7591
days old
2 comments
2 participants
participants (2)
-
elf＠ucsd.edu -
mouse＠Rodents.Montreal.QC.CA