Tektronix 4014-1 troubleshooting advice

[Pontus Pihlgren]

Hi

We have a 4014 at the computer club and that patterns looks very 
familiar. It usually clears after a minute or so.

We have assumed it was normal and have not investigated.

Congratulations on a nice find! I'm quite jealous.

/P


On Thu, Mar 26, 2015 at 10:03:03PM -0700, Josh Dersch wrote:
> 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
>