On Tuesday 29 April 2008 22:57, Wiebe Cazemier wrote:

I can't be sure, but it seems the blue gun has become much less sensitive,
and that the problem now is mainly is the red gun. Maybe it's wishful
thinking, because that would mean that it was some dislodged particle, but
I'd rather not assume the worst yet, so...

Would anyone know if trinitron tubes have particularly fragile heater/cathode
constructions?

The repair FAQ has a comment about having to tap the neck quite hard: "not
enough to break it, but close". How fragile is the neck? It would be
difficult to describe how hard I could hit it without breaking it, but any
advice is welcome.

I've got an additional question. When I put my continuity meter on the GND and
R or B pin, I can't produce a short by any amount of tapping. A very brief
intermittant short should be very clear, because it has an audible beep.
Because I can only reproduce the fault when it's cold, having the heater
turned off would seem ideal.

What I want to do, is remove the neck board and do some more testing. Do I need
to discharge the tube for this? I would guess not, but I thought I'd ask.