VT101 screen adjustment

[Christian Corti]

On Tue, 10 May 2016, tony duell wrote:
>> Yes indeed. Fortunately this one wielded under my trimmer and all is
>> properly aligned now. All I need to do now is troubleshoot the keyboard
>> circuit which I hope is the same as the VT102...
>
> In general it is a bad idea to cure faults by adjustments. Unless somebody
> has been twiddling, these adjustments only drift if some other component is
[...]
> My guess is a capacitor is failing. So far you are still within the range of the
[...]

The most common failure in such alignments (like vertical linearity) is 
dirt/dust/oxide on the wiper of the adjustment potentiometer, so just 
turing it back and forth usually cures the problem. If not, *then* there's 
another problem.

Christian