20 Aug
2004
20 Aug
'04
11:20 a.m.
There are dangerous voltages on the analog board of
that machine.
Perhaps even FATAL voltages.
You're more likely to get hit by a car than get zapped by your
Macintosh
if you take simple precautions, like unplugging it from the wall for
example. properly
drianed it can throw you across the room. (well at least TV crts can.)
However the charge is unlikely to be fatal. I have been zapped a couple
of times, the worst was from the EHT supply in a Barco monitor when the
unit was switched on, and when a transistor on the EHT regulator PCB had
failed so the EHT was sitting at about 32kV. It deceid to flash over to
my fingers. And yes, I lept across the room.
However, it is _darn hard_ to connect yourself to the EHT in a Mac (or in
any other monitor) unless you are working on that area. The EHT connector
has a nice insulated rubber cover on it. The EHT rectifier is inside the
flyback transformer -- there are just no bare connectiosn to touch. The
only problem comes if you disconnect the EHT connector from the CRT to
remove the CRT or the analogue board (or replace the flyback
transformer).
-tony