Jerry G. wrote:

There's probably dirt holding it back.

The cause is usually from bad capacitors in the vertical deflection
circuit. With age, they can become thermo sensitive. You can find these
with a heat gun, cooling spray, and an ESR meter.

Hi Jerry...

Thanks very much, appreciate it. Seemed to be extra dried
up flux on the edges of the board.

Hoping that just a reflow will do, given that I can turn it
on and off with just a bit of a tap on the case, but if not
I'll be sure looking at the caps

Oh - one more thing... I retired before these things came
out... wouldn't mind touching it up while I'm at it.
Is there no longer a service switch (or jumper) to
completely collapse vertical?

Thanks again, and take care.

Ken