The major problem with the original board is that over time, being subjected to repeated shock and vibration, the large resistors break away from the circuit board, causing one or more of the InfraRed leds to fail. This typically results in multiple balls in play or endless multiball. Later versions of the board used a rubber grommet shock mounting system, but this was not enough to solve the inherent flaw in the system.
Some other shortcomings in the original design include high current consumption and heat generation, lack of indicators showing the status of the IR LEDs, and and just plain flimsy PCB construction.
The newly redesigned board has a number of significant advances that improve over the original:
- No more 2 watt resistors! This board utilizes extremely low-mass chip resistors which will not stress the solder joints under repeated vibration.
- Tapered PCB conforms perfectly to the space provided and is significantly stiffer than the original, reducing board flex. Larger traces and pads for better reliability and longevity.
- Better IR efficiency. The original design used about 280mA of power to drive the LEDs. By chaining the LEDs in series, not only was the current increased for more transmissive power, but the overall current consumption has been reduced to approximately 120mA!
- Visual status LEDs have been added to the reverse side of the PCB, allowing them to be easily checked from outside the machine! Two green LEDs show the status of the two IR LED chains. One red LED indicates power being delivered to the board.
