My until-very-recently-working Amdek Color-I RGB Monitor (November 1983) has
given up the ghost. It was working perfectly the last time I powered it up, but
now it doesn't turn on. No noise, no hum, no glow, nothing, it's just silent,
as if it died in its sleep. (It's worth noting that it was left un-plugged
between the last time I used it and now, so I don't think it was a surge).
I'm embarrassed to admit this to the many old veterans on this list, but while
I am not sure why you're ashamed. IMHO realising that you don't know
something (nobody can know everything!), and asking for advice is a very
sensible thing to do. Not something to be ashamed of.
I have a good history of working with digital
electronics, CRT repair is well
outside my scope of experience. Still, I'd really like to fix this guy and get
it working again, so I would greatly appreciate any newbie advice that anyone
has to offer before I open the monitor up and start poking around (ginerly, for
fear of dying). My first step was naturally to google 'Amdek
+"Color-I"' and
The hazards are overrated!. The most dangerous voltages in most monitors
[1][ are the mains and things derrived directly from it (the 350V DC on
the primary side of an SMPUS, for example). The 25kV EHT to the CRT will
give you a belt, but is less likely to kill you (due to the high source
impdedance, it can't supply much current). It's also well insulated. The
main danger, actually, is that a shock will make you jump and then break
the CRT or something.
[1] The exception is that a few monitors, a very few monitors, mostlu
vector displ;ays (the DEC VR14 is one such) get the EHT using a step-up
transofrmer from the mains (rather than from the flyback transformer).
This sort of EHT supply has a fairly low impedance and can be lethal.
Lethal as in 'Touch it and you won't feel anything. Ever again'.
Never work with botjh hands -- current flow hand-to-hand is the most
dangerous. Most old-timers keep their left hand in their pocket. And
always assume every point is live until you've proved it isn't.
If it's as dead as you say it is, the problem is probably in the PSU
area. The first thing to do is to work out if it is an SMPUS (likely) or
if there's a mains-frequency transformer.
-tony