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The PP7A power supply

PP7A is a switching power supply located in a metal cage on the left side of the monitor (in a cabinet shown here), behind the coin mechanics and the coin box.

PP7A power supply

On the top of the plug you can check voltages by applying the probe during attract mode. In a working game they were:

pin voltage pin voltage pin voltage pin voltage pin voltage
6P-4 4.88 V 6P-6 -5.07 V 6P-3 12.04 V 7P-1 0 V 9P-9 23.33 V
6P-5 4.88 V 7P-7 -5.06 V 7P-5 12.04 V 7P-2 0 V
7P-6 4.88 V
9P-8 -5.04 V 9P-4 12.04 V
9P-6 4.86 V 10P-1 -5.03 V 9P-5 12.04 V
9P-7 4.83 V 10P-2 -5.03 V
10P-9 4.83 V 10P-3 -5.01 V
10P-10 4.86 V 10P-4 -5.02 V


Replacing a PP7A power supply

If you have a defective power supply and you are not willing or able to repair it you can easily replace it by using two switching power supplies, one for the +5 and the +12 volts and another for -5 Volts.

The reason for the necessity of two supplies is that the CLK board with its ECL logic draws a large current of several amperes at -5V.
The original power supply has the following specs

+5 V DC  up to 7.5 A
-5 V DC  up to 6.5 A
 +12 V DC  up to 100 mA
 +24 V DC  up to 200 mA


The 24 Volts are being used for the game counter and can be omitted if necessary

A very good replacement for the PP7A power supply are two PC power supply units from old PC's. I used two identical Magnetek power supplies which are too weak for modern PC's (only 65 W per unit) but can be used as a Nintendo replacement PP7A without problems

You will have to wire them in the following way: