Hello All,
I need some help on a Defender Arcade game.
I cant get the 5 v supply to work on the power supply board.
Now here is the puzzle , I bought another power supply board
rebuilt both with Bob Roberts kits. Both are still missing the 5 v
lights , but both have 12 , -5 volts.
I checked all fuses and resolder all pins and clean board.
Recconnect to machine (only plugging in the 4J1 connector :
>>> On Board Readings
>>> Pin 1-3 10.83 Acv
>>> Pin 2-4 10.83 Acv
>>> +12v and -5 v working
IC 1 pin 12 0 volts
I connected a 23 volt centertp Transformer and it worked (5 volts)
on both power supply boards
The main transformer has 23 volts ,
On the test bench with center tap transformer it works... 27vDC on pin 12 IC1
Connect to machine transformer IC1 pin 12 is at 1/2 volt ( both power supply boards)
Three circuits on the board 5 , 12,-5 volt , if there were a conflict neither or all would not work correct..??
But 12, -5 work and scope them out clean with no spikes..
I am puzzle by this simple circuit, I knew I had the all parts in correct... Now it turning out to be
Transformer.. or ??/
I need some help on a Defender Arcade game.
I cant get the 5 v supply to work on the power supply board.
Now here is the puzzle , I bought another power supply board
rebuilt both with Bob Roberts kits. Both are still missing the 5 v
lights , but both have 12 , -5 volts.
I checked all fuses and resolder all pins and clean board.
Recconnect to machine (only plugging in the 4J1 connector :
>>> On Board Readings
>>> Pin 1-3 10.83 Acv
>>> Pin 2-4 10.83 Acv
>>> +12v and -5 v working
IC 1 pin 12 0 volts
I connected a 23 volt centertp Transformer and it worked (5 volts)
on both power supply boards
The main transformer has 23 volts ,
On the test bench with center tap transformer it works... 27vDC on pin 12 IC1
Connect to machine transformer IC1 pin 12 is at 1/2 volt ( both power supply boards)
Three circuits on the board 5 , 12,-5 volt , if there were a conflict neither or all would not work correct..??
But 12, -5 work and scope them out clean with no spikes..
I am puzzle by this simple circuit, I knew I had the all parts in correct... Now it turning out to be
Transformer.. or ??/

