Re: G05-802 focus issue

Does it get any better after 15 - 20 minutes of operation?

-Mark

On Fri, Jul 23, 2010 at 3:21 PM, Darren Finck <dgfinck@yahoo.com> wrote:

> I like the way you think, Rodger. All good points. Focus on the simple
> stuff first.
>
> I have thoroghly cleaned the screen, the overlay films, and the
> half-silvered mirror. However, the out of focus observation was made with
> the monitor out of the cabinet and with the overlays off.
>
> I did not mention that I have adjusted the brighness and contrast as
> follows:
> 1) both down all the way
> 2) increase brightness until vectors are just visible
> 3) increase contrast until the display is bright enough to play in a
> semi-darkened room.
>
> I will try tweaking the brightness/contrast pots some more this evening to
> see if I can obtain better focus.
>
> Thanks again,
> Darren
>
> --- On *Fri, 7/23/10, Rodger Boots <rlboots2@gmail.com>* wrote:
>
>
> From: Rodger Boots <rlboots2@gmail.com>
> Subject: Re: VECTOR: G05-802 focus issue
> To: vectorlist@vectorlist.org
> Date: Friday, July 23, 2010, 10:28 AM
>
>
> Check that screen & overlay are clean. Try reducing brightness.
>
> On Jul 23, 2010 9:24 AM, "Darren Finck" <dgfinck_at_yahoo.com<http://mc/compose?to=dgfinck@yahoo.com>>
> wrote:
>
> OK, I'm working on the G05-802 that came in my Battlezone. I have already:
> -resoldered cracked joint at header on EHT board
> -replaced a bad deflection amp xistor
> -replaced all of the electrolytics (except for the big 6800uF power filter
> caps) on both boards
> -replaced the big wacky diode on the EHT cage (D904, H1809?)
> -adjusted the HV to 12kV with no signal inputs
>
> Now it works more or less fine, except...
>
> I can't get it to focus well. I can adjust it from end to end, and there's
> an area in the middle where it's "best," but still nowhere near as sharp as
> the V2000 in my Asteroids. I've checked the focus voltage coming off the EHT
> board (pin 1, or 8, depending of which version of the schematics you're
> looking at) and it is varying from 0 to 370V as I turn the pot. The G2
> voltage is, of course, running about 370V.
>
> Does this sound like a worn-out cathode? Or a tired HV transformer? Or is
> there something else which might be preventing it from focus properly?
>
> Thanks,
> Darren
>
>
>

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Received on Fri Jul 23 16:25:29 2010