VT420 terminal screen

[Peter Allan]

I have a DEC VT420 terminal which works pretty well. However, I am
concerned that sometimes the characters on the screen seem to get torn
sideways and jump around a little on a timescale of less than one second.

My guess is that there is some issue with the power supply, but that is
just a guess.

Does anyone have any experience of this and know what I should look at in
order to fix it. If it never gets worse, I can live with it, but I fear
that one day it will just die.

Cheers

Peter Allan