Inexpensive Jamma Supply being sold on Ebay and Elsewhere
(with hidden issue)


They are offered with following specs.

Universal AC input/ Full range
Low cost, high reliability
High efficiency, low working temperature
Built-in EMI filter
100% full load burn-in test
Low ripple & noise
Protections: short circuit/overload/over voltage
DC output: +5V/10A +12V/5A -5V/1A
Input voltage: 100-220VAC
Input frequency: 50-60Hz
Impulse current: cold start, 20A at 115V, 40A at 230V
Overload protection: 105%-150% hiccup mode, auto-recovery
Overvoltage protection: 115%-135% rated output voltage
Set up, rise, hold up time: 800ms, 50ms, 20ms/115VAC
Pressure: -I/PO/P, I/PFG1.5KV/min
Working temperature: 0-50 @100%, -10@80%, 60@60%
Safety standards: Correspond to UL1950, EN60950, CB, CE
Interface type: 8P/9.5mm pitch terminal block with cover

All appears to be accurate EXCEPT there is NO -5V/1A
It was never implemented on the current version of this supply
The decision  to remove this portion of the power supply was most likely a cost cutting move.
They have sold a lot of them, and since most boards connected to this will not need the -5V the new owner will never know it's missing, or
worse think it's failed at some point and buy another.

Most Jamma boards do not require -5V to function.
However there are some arcade boards that will not function without it.

Below are the details to correct the omission of the -5v supply voltage so this can be used with any arcade board it's needed for.

This is the board, solder side removed from the case. The terminal circled is the -5V Screw post bottom.
As you can see : it is connected to nothing as sold
I've scribed on the board AC,Gnd, +12, +5, and -5 as marked on the terminal strip label.

Above is what we need to add to the board to restore the missing voltage.

I took the source input for the LM7905 from the +12v source before the rectifier.
Here is where I placed the parts.

I used a small dremel drill bit to place the component holes in positions that I thought worked best.
This photo shows the placement of the components, including the LM7905 -5V regulator, before change.


I found the regulator was getting too hot when a game board needed the -5V,  in one case it failed.
The regulator needs to be on the heatsink. Either use insulators to mount it to the heatsink using the hole provided on the right. (best solution)
Or cut the foil at the one side of the heat sink mounting to isolate it from PCB ground and mount the regualtor directly to it.
(see dotted line on board bottom). Mount at hole on right, then wires can extend it's connections to the points shown.
If mounted directly insulate the heatsink from the top case, and do not secure it to the case top with original screws.

Mounting the regulator with insulators, eliminates the need for any changes in case mounting or cutting PCB

Parts Needed
  1pc.-2A pwr diode
                                                                                                             2pc.-1uf electrolytic  (any )   
                                                                                                             1pc.- LM7905 (-5v regulator)
                                                                                                             1pc.- wire jumper
                                                              1pc- mounting screw & nut  (to secure regulator to heatsink

That did it. Now all the posts on the CP10A provide the voltages as stated on the label!,  including -5V