CRT mold

[Scott Stevens]

On Sun, 13 Feb 2005 10:07:38 +0000
Gordon JC Pearce <gordon at gjcp.net> wrote:


> I supppose the answer would be to get a "bad" tube (excessive screen 
> burn, low emission, gone soft, physically damaged) and smash it open
> to measure the thickness of the faceplate.  It's easy to break up CRTs
> 
> safely - just knock the evacuation tube off the end of the neck, air 
> will rush in, and no, the tube won't implode.
> 
> Gordon.

It's easy to evacuate the air that way without even trying, on some
types of systems.  The compact Macintosh (128K, Plus, SE, SE/30) has a
long portruding glass nipple on the neck of the CRT between the pins. 
This tightly fits into the socket, which is mounted on a small circuit
board.  The circuit board 'nicely' amplifies the torque applied to the
glass nipple.  It's VERY easy to inadvertantly apply pressure against
that board when pushing and pulling cables and parts inside the Mac's
chassis.  Hearing that sucking sound as the air rushes in really, well..
sucks.

The dinkyscreen Macs were definitely NOT designed to be user servicible
for this, and other reasons.  Luckily it's one of the easier CRTs (nice
and small) to pull out of the case and replace.

-Scott