Tektronix 4014-1 troubleshooting advice

[Josh Dersch]

Hi all --

Picked up a Tektronix 4014-1 terminal.  It's in pretty good shape, nice 
and clean and it's in nearly-working condition except that the storage 
behavior isn't quite right.

On power-up, write-through doesn't.  (That is, characters don't get 
stored to the tube.)  Clearing the display via the RESET/PAGE key clears 
a roughly elliptical region in the center of the display but leaves the 
outer edges a mess.  The cleared region stores characters properly.  You 
can see the overall effect here:

http://yahozna.dyndns.org/scratch/tek4014/clear.jpg

After a 2-3 minutes of warming up the area cleared by RESET/PAGE 
increases.  I haven't run the terminal long enough to see if it 
eventually completely erases the screen (while the power supply appears 
to be within tolerances, I still need to rebuild/reform it so I'm not 
going to run it too long yet).

So far everything else seems to be functioning properly, the cursor 
appears properly (and does not write through), input is accepted from 
the keyboard, etc. I've been reading through the service manual on 
Bitsavers and it describes a very in-depth alignment procedure which I'm 
prepared to go through (once I've got the power supplies rebuilt) but I 
thought I'd ask here if this problem rings any bells and if there's 
anything I should immediately suspect or adjust.  You guys know 
everything :).

Thanks as always for the advice,
Josh