Re: Monitor problem

[Giorgio Morocutti <giorgio.morocutti@alice.it>]

On Fri, 01 Feb 2008 15:27:04 +0100, Giorgio Morocutti
<giorgio.morocutti@alice.it> wrote:

>On Thu, 31 Jan 2008 17:32:59 -0800, "Michael J. Mahon"
><mjmahon@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!
>
I have replaced the old cap with new, but nothing is changed.
:-(
Have you another suggestion?

Thanks

Giorgio

Giorgio Morocutti
giorgio.morocutti@alice.it
Apple II & Apple III forever !