midway space invaders cocktail game not working

security0001

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the game doesn't come on at all. i checked the p/s and adjust the +5, -5, & 12v and they are testing at 5.10, -5.10, 12.20. i checked all the fuses and replaced the s/b and they are not blowing, my lights on coin door and controllers work. i put another board set in it that i know used to work and still all i get is the monitor on and lines vibrating on the screen, no sound or game at all. any help would be greatly appreciated. this is a midway space invaders cocktail model. thanks
peter
i have a good picture of the screen but its too large to attach so send me a PM and i can email it to you if needed.
 
almost same issue

i have just about the same problem but i can hear the sound very lightly playing coming from the speaker i hope someone has the answers for us
 
Now did you measure the power supply while it was connected or Not connected?
space invader power supply don't have the Highest current rating.
You can install a bob roberts cap kit into the power supply sometimes that does boost up the current.

If you have an esr meter. You might want to check caps see attach pic

http://www.brentradio.com/SpaceInvaders.htm

+5v DC A 1 +5v DC
+5v DC B 2 +5v DC
+12v DC C 3 +12v DC
+12v DC D 4 +12v DC
-5v DC E 5 -5v DC
No Connection F 6 No Connection
KEY H 7 KEY
No Connection J 8 No Connection
No Connection K 9 No Connection
No Connection L 10 No Connection
No Connection M 11 No Connection
No Connection N 12 No Connection
No Connection P 13 No Connection
Ground R 14 Ground
Ground S 15 Ground
Ground T 16 Ground
Ground U 17 Ground
No Connection V 18 B+W Video Signal

There are caps on the sound board.
If you have a Volt meter you can read the voltages across cap c43 You should see 12 volts across the cap. Circle in yellow. The cap circle in red should be 5 volts.
 

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the game doesn't come on at all. i checked the p/s and adjust the +5, -5, & 12v and they are testing at 5.10, -5.10, 12.20. i checked all the fuses and replaced the s/b and they are not blowing, my lights on coin door and controllers work. i put another board set in it that i know used to work and still all i get is the monitor on and lines vibrating on the screen, no sound or game at all. any help would be greatly appreciated. this is a midway space invaders cocktail model. thanks
peter
i have a good picture of the screen but its too large to attach so send me a PM and i can email it to you if needed.


If you're getting jibberish on the screen that really isn't doing much, on a known working board... and you're sure the voltages are correct when the game is connected to the power supply; check the reset line. It should be grounded when power is applied, IIRC (had the same issue with mine, and a friends... so I guess it's a common thing?). There should be a small circuit for it on the power supply and if that goes bad, then it won't get grounded and the game will just sit there and, basically, do nothing.

Should be pin 6 on the 16 pin connector.
http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=pinout&page=SpaceInvaders.txt
 
Last edited:
my problem ended up being the reset circuit on the power supply. the diode in the reset circuit had a cold solder joint. one leg just pulled right out of the board when i checked it, so i resolded and it came up and worked.
thanks
 
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