"Wiebe Cazemier" wrote in message
b.home.nl...
On Sunday 27 April 2008 23:47, James Sweet wrote:
I would desolder the blue cathode pin on the CRT
socket and tap the neck with the monitor on. If you can still repro the
symptoms, then the problem is probably in the tube.

Taking what bz said into account, that the Trinitron tube has a single
electron
gun, doesn't this mean that if the screen turns fully blue (and not red
and
green as well, meaning white), including retrace lines, that the short can
exist nowhere except inside the tube?

The Trinitron tube has a "unified" electron gun, it's more marketing than
anything else, but in a nutshell it uses the same focus and accelerating
electrodes for all three cathodes. There are still three separate guns in
effect, just bundled into one tidy assembly. Electrically it is no different
than the three separate gun assemblies used in other CRTs.

You will not damage anything by disconnecting a cathode, the accelerating
anodes, grids, focus, etc will still be active.