Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting,rec.games.video.arcade.marketplace (
More info?)
Ok, pulled H ROM off the board. Booted it up. Got the 16 vertical lines:
Adjusted a couple of pots under the monitor to clear up the image:
http://members.shaw.ca/scaredstiff/pics/P3140028.JPG
You can see the darker area that moved across the screen.
Pulled G ROM:
http://members.shaw.ca/scaredstiff/pics/P3140029.JPG
It also has the dark lines that go thru it. I closed the slam switch on the
door:
http://members.shaw.ca/scaredstiff/pics/P3140030.JPG
Lines moved and sort of cleared up a little,
http://members.shaw.ca/scaredstiff/pics/P3140031.JPG
Seems to have almost a ghosting between the lines. Again you can see the
dark area in the center that slowly goes from right to left. And finally:
http://members.shaw.ca/scaredstiff/pics/P3140032.JPG
will all the roms removed.
Reseated the roms, checked that they are properly seated. Wouldn't boot.
Adjusted the main connector on the board, it boots, but we're back at square
one again.
You can play the game, sound works fine, but as soon as you start clearing
the screen, it becomes worse, garbled graphics where finally in the end, you
can't see anything.
I don't have any ram chips kicking around. It maybe a little hard to find
them now.
I'm in the ball park I think, but nothing I've tried works. Shorting out the
ram next on pin #7?
Any other suggestions?
--
Later.
D.E.
Have a better one.
To reply, simply remove:forgetthespam.
"Matt Rossiter" <rossiter@ni.net> wrote in message
news:Ll%Yd.17794$Pz7.1927@newssvr13.news.prodigy.com...
>I would suggest glancing over the first 15 pages of this document.
>
http://www.ionpool.net/arcade/midway/midway_8080_test.pdf
>
> Get yourself some 2101 rams. If you do the "vertical line test" as
> described in this document - you can sometimes piggyback a new ram over
> the
> suspected bad ram and see if that makes the problem go away. If it does,
> just replace the bad ram.
>
> If your board is strapped for tms2716 roms, you could also try the test
> rom,
> which you can download here.
>
http://www.ionpool.net/arcade/tech/space_invaders_test_rom.zip
>
> By the way, just because you are seeing symptoms of a bad ram, it doesn't
> necessary mean there's a bad ram. Sometimes certain chip select lines
> might
> not be working. You might want to buy a cheap logic probe and test those
> as
> well. I believe it's pin 17 on the ram chips.
>
> Matt
>
>
> "Mark Hooks" <markhooks@earthlink.net> wrote in message
> news:ExPYd.2628$qW.50@newsread3.news.atl.earthlink.net...
>> If all else fails it's likely a bad RAM.
>>
>> Mark
>> ".D.E." <pinballguy6@hotmailforgetthespam.com> wrote in message
>> news:_JOYd.656864$Xk.430271@pd7tw3no...
>> > Tried that. Didn't make a change.
>> >
>> > --
>> > Later.
>> >
>> > D.E.
>> >
>> > Have a better one.
>> >
>> > To reply, simply remove:forgetthespam.
>> > "Mark Hooks" <markhooks@earthlink.net> wrote in message
>> > news:HcMYd.2134$qf2.265@newsread2.news.atl.earthlink.net...
>> >>A friend of mine cleaned the edge connector where the two board halves
>> >>connect together and that fixed his.
>> >>
>> >> Mark Hooks
>> >>
>> >> ".D.E." <pinballguy6@hotmailforgetthespam.com> wrote in message
>> >> news:YaMYd.658658$6l.189027@pd7tw2no...
>> >>> Well, I replaced the power connector today and still no change. The
> game
>> >>> plays, sort of, but the graphics are garbled and distort. Dark lines
>> >>> cross the game after a few minutes of playing.
>> >>>
>> >>> I checked and reseated the game roms. Thought that the power
>> >>> connector
>> >>> was flaky, so I replaced that. NO change.
>> >>>
>> >>> Someone suggested replacing the electro caps beside the daughter
>> >>> board
>> >>> and main board connector. Anyone know EXACTLY which types these are?
>> >>> I
>> >>> tested mine and they seem ok.
>> >>>
>> >>> Any other suggestions?
>> >>>
>> >>> This is getting frustrating.
>> >>>
>> >>> Thanks.
>> >>>
>> >>> --
>> >>> Later.
>> >>>
>> >>> D.E.
>> >>>
>> >>> Have a better one.
>> >>>
>> >>> To reply, simply remove:forgetthespam.
>> >>>
>> >>
>> >>
>> >
>> >
>>
>>
>
>
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