5 Dec
2007
5 Dec
'07
3:25 p.m.
On Monday 03 December 2007 23:23:01 Tony Duell wrote:
Well, it could be -- the A1/g2 supply often comes from a half-wave
rectifier hung off the flyback. It's thus charged by a pulse essentially
at the baeginning of each line, so a low-value can cause an 'iuteresting'
display.
The fualt I was thinking of was actually a leaky capacitor, part of the
RC filter network on the A1 supply. It was pulling the supply down, of
course. The series reisstor was fine in this case, and yes I have had
high-value resistorrs go even hihgher, or open.
-tony
Then, if it starts to fade, I can re-check them
and see if the problem is
the CRT loosing emision or something cheaper to fix like the 1st anode
(g2) voltage going low due to a dead capacitor.
I spotted this and thought "Aha, capacitor? Usually a resistor going high in
my experiece! I'll reply and set this person straight". Then I spotted it
was Tony, and now I'm keen to see what bizarre set of circumstances he
diagnosed where a failing cap caused this. I really hope it's nothing as
prosaic as a failing smoothing cap in the A2 supply... ;-)