Leon Borre Bally & Stern Lamp Driver Board Repair
Repairing Bally and Stern Lamp-driver boards
Attention: this procedure is the next part of repairing a solenoid-driver boards, so please look at this guide first...... 
To repair a "lamp-driver- board".. Of course there is the lamp-test on the flipper itself which will light all bulbs. There are 3 disadvantages: it does not work easy, you have to bend over your machine; light bulbs can be broken; light bulb holders can be broken or oxidised.. To be sure the board is OK you can apply the following method.
Method:
Take the board out of the pinball machine and connect a power supply. To do the tests we'll connect a box with 4 switches and a button, and to view the results we'll connect a series of leds. The same way as to repair the solenoid driver board.(see first)
Material needed:
The box with switches is the same as for the solenoid driver board tests....... but now there's another connector added to use on the lamp-driver board
4 switches and a button at the side.
The connector goes to J4 on the lamp-driver-board and is connected in the following way:
Switches 1, 2, 4 and 8 to pins 14, 15, 16 and 17, the push-button is connected to 4 pins: 4,5,6,7. The other side of the button and switches is connected to the mass.( by the blue wire,see photo)And to finish: pins 2 and 3 do not go to the box but get seperate pins (a red and black one) because this is where the power is attached to. 5 volts connects to pin 3, mass (0 volt) goes to pin 2.
Connected it looks like this:
The new plug is connected to J4, mass is connected to TP2-GND.The 5volt supply is connected.
The power supply is the same as for repairing the "solenoid-drive-board" with 2 female plugs attached (in matching colors) !!
Red goes to 5 volt, Blackto 0 or mass.
The control-panel with 28 leds is new, to check all connectors at once, schematically it's very easy.....
Before mounting the leds try out witch side of a led needs to be connected on the and witch side on the mass......(reversed the will not light up...)
Use a universal board with 2 times 14 leds. On the bottom side are the resistances and the connector plug so you're able to connect it to the "lamp-driver-board" This strip is the same type you use to create IC-sockets, the distance between the pins is exactly what you need to put it on the connector of the lamp-driver-board....
de strips
..............................bottom side of the board
................................................................The arrow shows the connector strip
Finished :.......... 
Connected it looks like this......
Inserted in one of the output-connectors, the red common lead connected to TP1 - 5 volt.
Usage:
Take the lamp-driver-board out of the pinball machine. Connect the switches to J4, the connector on the right place!!!! The common blue wire on the GND TP2 . And connect the power supply..
The led-control-panel on the connector you want to test, this can be J1, J2 or J3. His red common lead to TP1 5volt.
Now you can use the switches to get 15 different combinations, like when you test the solenoid driver board. When you put it to one of the combinations push the button and some of the leds should light. Note that the leds will not go out until you disconnect the power. This is because the drivers are 'triacs' and they keep 'going' until the power is switched off. Here you find a list of all tests:
Connector J1: .............output ....Con. J2..output.....Con. J3...output
.......................................pins........................pins.................pins
Switch1 button...........none ...................1/2/14/15..............none......
Switch 2 button..........none ...................6/7/16/20 ............none.....
Switch 1 2 button........none .................10/11/22/23...........none....
Switch 4 button.........27/12 ...................3/4/12/13 ..........14/24...
Switch4 1 button.........4/26 ...................5/8/9/21 .............13/22..
Switch 4 2 button........11/25...................none....................18/20..
Switch 4 2 1 button....5/24.....................none ..................10/21..
Switch 8 button .........6/13/28 ..................none ..................2.....
Switch 8 1 button.......7/16 ......................none ..................4/27..
Switch 8 2 button......10/15 .....................none ..................3/23..
Switch 8 2 1 button..2/14 .......................none .................9/16..
Switch 8 4 button .....3/23 ......................none .................11/17..
Sch, 8 4 1 button ... 8/17 .......................none .................15/19..
Switch 8 4 2 button .9/19 .....................none ..................12/25..
Switch 8 4 2 1 button 1/18 ..................none ..................1/26..
On J1 pins 20/21/22 are not connected
On J2 pins 17/18/19 are not connected
On J3 pins 5/6/7/8/28 are not connected
If there are leds which already go on before you pushed the button, you may assume these pins have a shorted triac.. Use the schematic or follow the trace on the board back to its driver-triac and replace this........
If there are leds which do not work, use the same method to get back to the defective part. 99% chance this will be a broken triac !
Good luck!!
It is possible to connect the led-strip in the pinball machine, when you do a lamp test all leds should light, except for the pins which are not connected (look above). This is a extra quick control method to find out if all outputs (on the board) are ok!,