Galaga low voltage on Board

pinballdirec

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If I check the 5 volt on the main board it is about 4.75 volts, if I check it on the switching power supply it is 5.22. The game is playing but is flaky.

I ran a couple jumper wires from the power supply to the connector on the board and still had low voltage.

Should I just replace both connector, or should I run a new wire or any other ideas?

Kevin
 
If you have an adjustable power supply, turn up the adjuster dial until the board itself reads 5V (between 5V and GND). I have this problem whenever I play a game using a Converter to Jamma board. The Jamma harness and the converter board seem to have enough resistance to lower the voltage seen at the board - sometimes enough that the game won't even run until the voltage is increased.
 
I tried turning up the power supply, but If I got a red light on the power supply, the machine wouldn't boot up.


On many power supplies the over voltage kills the power supply and then lights the red light. This is to protect the board from getting fried from too much voltage.
 
Then, assuming your jumpers were adequate in size, something on the board is drawing it down. How was the board modified in order to bypass the on-board rectifier circuit?


I used a small alligator clip and jumped from the power supply to the connector on the board.


I'm not sure if I'm answering your question correctly, but I used a bob roberts switching power supply kit with the premade connector...
 
My question is confusing because I was thinking of Galaxian, not Galaga.

Is the board connector in good shape? If the connector is stretched out it will not make good contact with the power harness and could drop off voltage.


Another possibility is the connector solder joints are cold/cracked.
 
Is there anywhere else on the board I could jumper to just to test it.

Seeing as this is Galaga, there are actually two +5V supplies to the board. One on the edge connector, and the other on the 3 prong plug. In fact, there is a ground on the 3 prong plug as well (assuming you don't have a boot leg or non-original Galaga board). Did you jumper 5V to both the edge connector and the 3P plug?
 
Seeing as this is Galaga, there are actually two +5V supplies to the board. One on the edge connector, and the other on the 3 prong plug. In fact, there is a ground on the 3 prong plug as well (assuming you don't have a boot leg or non-original Galaga board). Did you jumper 5V to both the edge connector and the 3P plug?


I just jumpered the 3 prong plug, I didn't know about the other connection. I'll check the edge connector.
 
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