(Taking a bow) Glad it worked for you, and it WILL work for others!
Trust me, bad common/ground connections cause MOST weird problems...I've
worked on pinballs and videos for over twenty-five years, and the ones that
work the best (Williams!!) have by far the best common/ground connections.
Their boards are multi-screwed to the ground plane (a single metal plate)
and the plane and the boards are all tied firmly to the cabinet common, and
the earth ground connection. In fact one common problem with Williams
pinballs (off -topic but relevant here) is that when there are screws
missing that noise creeps rapidly into the game!
Get nice 16 - 18 stranded (just for ease in handling, solid wire will work
as well) gauge wire to tie all your commons together and join it to the
earth ground connection (green wire on the three wire power cord in North
America, and green/yellow overseas)
John ;-#)#
At 09:20 PM 07/04/2002 +1000, Marc Alexander wrote:
>My Star Wars with the 25" Amplifone in it always had the screen
>size increase briefly on the Death Star explosion scene, like I've
>seen mentioned here quite a few times!
>I had assumed it was probably the HV regulation but not thought much about it.
>
>I was giving my machine a general going-over and thought I'd better
>do what John Robertson (thanks John!) often mentioned, which was to
>run 5V and GND cables directly between the ARII and the game boards,
>and also run a ground cable between the game board and monitor
>(or similar, and also to help WG monitors or any game really, esp. Atari)
>
>I made the following modifications, and the picture is now rock steady
>and I've lost a bit of horizontal shake also that it occasionally had,
>it's great.
>
> 5V and GND cables between ARII and game boards (with 2pin connector
> inline).
> 5V and GND wires between main and avg boards (may as well), done on
> the heavy
> tracks right near the edge connectors.
> GND wire with inline connector between monitor GND and game boards GND.
> (done on X or Y GND wire into deflection board)
>
>Other mods:
> Jumper wired +Sense on ARII to 5V out of ARII )bypasses overvoltage
> Jumper wired -Sense on ARII to GND out of ARII )'frying' problem with age
> Placed 5V6 5W protection zener across 5V and GND out of ARII
> (after checking adjustment on bench below 5V)
> Adjusted ARII for 5.00V at game boards after reconnection
>
>I can't say for sure but I think a reasonable amount of audio hum is gone
>also.
>
>
>Cheers,
>
>Marc
>
>
>
>
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Received on Sun Apr 7 11:52:28 2002
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