[rescue] sun2 monitor repair

[Walter Belgers]

Hi,

Ibve rescued my second(!) Sun 2/120. It did not work, due to a
malfunctioning PSU. I got a new PSU (that apparantly has been a spare for all
these years - it looked new!) and now the system starts up. But, there is
nothing on the monitor. I have tried another monitor that did output
something, so it is definately the monitor and not the graphics card or
cable.

The monitor is a Sun2/Monitor part 540-1062-01. The transformer is outputting
two voltages (both about 60VAC) that goes to a rectifier. That in turn goes
into a PCB that connects to the high-voltage unit and a PCB hooked up to the
tube. All components look fine. I have resoldered all joints on the large PCB,
which had no effect. I see nothing coming from the tube (also not close to the
foot). I hear a slight hum that seems to be coming from the PCB hooked up to
the tube.

Does anybody know common failures of these kinds of monitors? Or a link to a
(generic) repair guide/flowchart? I understand the safety precautions w.r.t.
working with the high voltages in the monitor that keep there long after being
turned off.

Walter.