ADM-3A question

Charles charlesmorris800 at centurytel.net
Sat Aug 10 10:33:56 CDT 2019


I decided just to fire it up and see if anything blew... it issued the 
expected beep as it came up.
Set the switch to half-duplex and it does actually echo bell (Ctrl-G) and I 
can see the screen moving as I type!
But there  is some kind of garbage every other row, although the cursor 
moves and the screen will "clear" (except for the 12 rows of garbage).
Power supply is 5.11 volts. So far so good.

Unfortunately the screen rot is even worse than I thought - the PVA layer is 
so opaque and bubbled it looked like cottage cheese once removed, and I 
can't make out what characters are on the CRT... I took the monitor out 
(very easy disassembly). I didn't even have to use a heat gun or a hot wire, 
just started at one corner, applied a steady and gentle pull, and it came 
off in one sheet with a giant sucking sound.

That oily mess took a while to clean up. I also scrubbed off the black 
anti-reflective coating since it was significantly scratched and peeled 
anyway.
Now waiting for the bead of clear silicone (around the outside of the plate 
only) to cure. I'll make sure it's air tight so no black dust will get in 
there by electrostatic attraction.

I can fix the RAM problem once I can see what is actually on the screen! ;)
Also the wire bracket with threaded ends that holds the flyback to the 
monitor chassis is missing one end entirely, so I need to fix that (keep the 
core halves firmly together).
Looks like I didn't get TOO bad a deal for $200 shipped, especially with 
upper-case installed. 


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