Tektronix 4014-1 troubleshooting advice

[Josh Dersch]

On 3/30/15 12:08 AM, Simon Claessen wrote:
> we have a working 4002a in our museum and I always let it warm up with 
> a completely illuminated screen for a minute or 5 before clearing the 
> tube for the first time. that seems to do the trick.

I finished restoring the 4014's power supply this evening and as a few 
of you suggested, leaving it to warm up for a few minutes seems to do 
the trick; after 3-5 minutes the screen clears fully and everything 
works as expected -- the stored characters stay crisp (they don't bloom 
or fade) and the picture is nice and bright.  So that's good!  Probably 
a few things are a bit out of tolerance, but I'll accept this behavior 
rather than risk making things worse by trying to recalibrate it :).

Tomorrow (er, later today, I suppose) I'll actually hook it up to a 
computer and throw some graphics at it...

Thanks all!
Josh


>
> On 27-03-15 06:03, 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
>>
>>
>