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Author Topic: Asteroids Monitor issues  (Read 3206 times)
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Netropolis
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« on: November 04, 2015, 08:42:37 pm »

My asteroids has been acting up.
Sometimes it works great, sometimes 1/2 a screen - a smack to the side of the cab fixes that - sometimes a bright dot in the center with faint lines going to all the asteroids.

I would like to reflow all the joints first. The smack fix gives me the notion it is a poor connection somewhere.

I seem to remember though, standard discharge tool = bad??
Is there a special tool/technique required to discharge the vector. XY monitor? 

I checked youtube and all the available vids are grounded screwdrivers under the cup.

Advice please.



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1979 Atari Asteroids
1980 Midway Pac-Man (TOTAL Restoration Needed)
1981 Midway Galaga
1982 Atari Pole Position
1986 Atari Championship Sprint
1986 Williams Pin*Bot Pinball
1987 Atari Badlands
1988 Atari Tetris/19-1 Multi-Cade
60-1  DK Jr Cabinet
2002 Hanabi Japanese Slot Machine
iankellogg
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« Reply #1 on: November 05, 2015, 09:36:00 am »

i would check the deflection transistors and generally everything for cold solder joints, maybe reflow everything.

as far as the tool goes, you want to discharge the monitor slowly, just add some 1megaohm resistors in series with the alligator clip of your 'discharge tool'
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Netropolis
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Re:
« Reply #2 on: November 05, 2015, 10:42:10 am »

Hey Ian, yes a total reflow is first on my list.
As for the tool modification, do you have a picture of what I need to make? I don't quite understand and want to make sure I get it right so I don't kill the monitor (or myself).

My understanding of caps, transistors and resistors is limited to watching John change em in his videos. 

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1979 Atari Asteroids
1980 Midway Pac-Man (TOTAL Restoration Needed)
1981 Midway Galaga
1982 Atari Pole Position
1986 Atari Championship Sprint
1986 Williams Pin*Bot Pinball
1987 Atari Badlands
1988 Atari Tetris/19-1 Multi-Cade
60-1  DK Jr Cabinet
2002 Hanabi Japanese Slot Machine
iankellogg
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« Reply #3 on: November 05, 2015, 10:53:20 am »

are you using a screwdriver with a wire and alligator clip on the end?
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Netropolis
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« Reply #4 on: November 05, 2015, 11:29:35 am »

Yes! Thats exactly it. It was a wrist strap but I cut the wire and attached it to the nail-puller screwdriver. 

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1979 Atari Asteroids
1980 Midway Pac-Man (TOTAL Restoration Needed)
1981 Midway Galaga
1982 Atari Pole Position
1986 Atari Championship Sprint
1986 Williams Pin*Bot Pinball
1987 Atari Badlands
1988 Atari Tetris/19-1 Multi-Cade
60-1  DK Jr Cabinet
2002 Hanabi Japanese Slot Machine
iankellogg
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« Reply #5 on: November 05, 2015, 01:36:18 pm »

so what you need to do is disconnect that wire from the screw driver, and add a 1 megaohm resistor to the end of the wire and attach it back to the screw driver


so Alligator clip->wire->resistor->wire->screw driver
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Netropolis
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« Reply #6 on: November 05, 2015, 01:56:44 pm »

I am on it Ian! 
I will post a pic before I do anything.

Thanks a bunch!

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1979 Atari Asteroids
1980 Midway Pac-Man (TOTAL Restoration Needed)
1981 Midway Galaga
1982 Atari Pole Position
1986 Atari Championship Sprint
1986 Williams Pin*Bot Pinball
1987 Atari Badlands
1988 Atari Tetris/19-1 Multi-Cade
60-1  DK Jr Cabinet
2002 Hanabi Japanese Slot Machine
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