Re: Re: Star Wars shaky video

Yes I'm thinking its a bad dac also, I have other working sets that play
fine so the fault is on the avg board not the machine. I hooked up my scope
to the output of 7a and can see the noise there so the fault is probably
there or the dac
----- Original Message -----
From: "peter jones" <highwayman2000@mail.ru>
To: <vectorlist@vectorlist.org>
Sent: Sunday, July 09, 2006 3:47 AM
Subject: VECTOR: Re: VECTOR: Star Wars shaky video

>
> -----Original Message-----
> From: "simon" <simonjhanlon@btopenworld.com>
> To: <vectorlist@vectorlist.org>
> Date: Sat, 8 Jul 2006 19:36:41 +0100
> Subject: VECTOR: Star Wars shaky video
>
>> Hi Guys
>> I have been repairing a Star wars pcb that I bought off ebay. I dead so I
>> removed the avg board and self test started to work. I checked the avg
>> board and found some damaged traces, repaired them and the board now
>> passes all test and plays fine except the video is shaky. In self test
>> you can see small steps in the vertical lines on the grid screen. I guess
>> its a bad cap somewhere in the Y section but I can't find it. Has anyone
>> had this fault before? I have checked all the caps have both legs still
>> intact, no noise on the +15 or -15 lines.
>>
> could be power - you should recap anything that old anyway.
> that said, i assume your using a testbench psu that should flatline like a
> deadman.
>
> last time i saw a fault like that it turned out to be a bad dac, dac
> failures seem common on atari pcb's judging by the number i have with
> sockets fitted or missing chips.
>
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Received on Sun Jul 9 05:40:37 2006