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Groups > comp.sys.apple2 > #3067

Re: AppleColor RGB all-red display

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Grent wrote:
> On Oct 15, 1:41�pm, dog_...@macgui.com (D Finnigan) wrote:
>> Oh, yeah. To add: I do get recognizable video. I can see the IIgs
>> desktop,
>> icons, menubar, etc. It's just that everything is a shade of red. And
>> it's
>> all intense red.
> 
> Usually it was a choke that would cause the color shift that you were
> talking. Some how I want to say 47microheneries. There was one for
> each of the 3 colors. Not sure these green and black things that look
> like caps are them or if they look like a resistor that has a coil
> wrapped around it. Then again you could have fried something else.
> 

I stopped in with the local graybeard and showed him the schematics, plus
told him the testing that I'd done. His best guess was that the NPN
transistor that controls the red beam has failed. This is the transistor
that's near the inductor and 4.7k resistor on the CRT board.

I'm going to test it this evening (or tomorrow morning if it's too late) and
report back.

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AppleColor RGB all-red display dog_cow@macgui.com (D Finnigan) - 2011-10-15 17:38 +0000
  Re: AppleColor RGB all-red display dog_cow@macgui.com (D Finnigan) - 2011-10-15 17:41 +0000
    Re: AppleColor RGB all-red display Grent <grent3@gmail.com> - 2011-10-15 17:33 -0700
      Re: AppleColor RGB all-red display dog_cow@macgui.com (D Finnigan) - 2011-10-17 20:47 +0000
        Re: AppleColor RGB all-red display dog_cow@macgui.com (D Finnigan) - 2011-10-18 14:19 +0000
          Re: AppleColor RGB all-red display Michael J. Mahon <mjmahon@aol.com> - 2011-10-18 12:05 -0500
            Re: AppleColor RGB all-red display dog_cow@macgui.com (D Finnigan) - 2011-10-18 17:41 +0000
              Re: AppleColor RGB all-red display Grent <grent3@gmail.com> - 2011-10-18 23:27 -0700
              Re: AppleColor RGB all-red display Alex Freed <alex_news@alexfreed.com> - 2011-10-19 02:10 -0700
                Re: AppleColor RGB all-red display Michael J. Mahon <mjmahon@aol.com> - 2011-10-19 16:08 -0500
                Re: AppleColor RGB all-red display Kevin Dady <kevin@hackaday.com> - 2011-10-19 18:16 -0700
                Re: AppleColor RGB all-red display Alex Freed <alex_news@alexfreed.com> - 2011-10-20 01:25 -0700

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