On 19.06.20 9:02, Tom Lake wrote:
I have an ADM-3A dumb terminal and when I first turn it on the display is squashed and the top line is mangled. After five minutes or so the display looks OK but is a little jumpy. After a few more minutes, the display is rock-solid and stays that way until the next time I turn it on cold. If I turn it off back on, the display is still fine as long as I don't let the ADM cool off first. Does anyone know what the problem might be? What to look for?

Check for bulging caps. they are failing, and work best at a bit higher
temperature.