Re: Monitor problem

[Allen Bong <allenbsf6502@gmail.com>]

On Feb 1, 10:27 pm, Giorgio Morocutti <giorgio.morocu...@alice.it>
wrote:
> On Thu, 31 Jan 2008 17:32:59 -0800, "Michael J. Mahon"
>
>
>
>
>
> <mjma...@aol.com> wrote:
> >Michael J. Mahon wrote:
> >Looking at the schematic, I'd suspect C206, a 220uF, 90v
> >electrolytic that filters the supply controlling the
> >cathode voltage.
>
> >It looks like this value was chosen high enough to keep the
> >cathode biased above the grid for long enough to prevent
> >the un-scanned spot from appearing.
>
> >There are other possibilities, but that's what I'd try first.
>
> >The simplest thing to do is to substitute another known-good
> >capacitor of at least 200uF and at least 90v rating.  If that
> >cures the problem, then replace the capacitor.  (Bridging the
> >old cap with the new one might work, too, but there's a chance
> >that it's electrically leaky, which would interfere with bridging.)
>
> Thanks Michael!
>
> work in progress ...
>
> Giorgio
>
> Giorgio Morocutti
> giorgio.morocu...@alice.it
> Apple II & Apple III forever !- Hide quoted text -
>
> - Show quoted text -

Hi Giorgio,

May I have the schematics as well.  I have an Apple monitor having the
same problem as you described.  I would very much like to open it up
for a check but a schematic would be helpful.  Thanks.

My email is allenbsf6502 at yahoo dot com

Allen