Soldered capacitor onto optical receiver board. Reinstalled transmitter and receiver. The switch matrix entries are now all good. Game now seems to play fine.

Got LED transmitter board working. To do: put capacitor on receiver board.

Details:

• All transmitter LEDs except #1 and #6 were failing or (in the case of the one Caleb removed) missing. I’m not sure if anyone had messed with LEDS 2,3,5 or 7, because several of these had been working just a couple weeks ago.
• Tested all resistors, all are perfect.
• Replaced LED #1 (the working but nonstandard one) + the missing LED #4, + all failing LEDs with original WPC-95 original specification LEDs. All are now transmitting well, see phone camera pics.

Note: our “PocketPD” DC power supply appears to be broken. At William’s suggestion I dug the extra fused bridge rectifier out of our “pinball electronics” box, and ran it to the right voltages using the big orange variac (see pics). This let me test emissions without having to be hooked up to the machine.

One of the LEDs that had been replaced last was shorted. The capacitor on the receiver board was bad. Removed both and need to order parts. We should probably change all the LEDs on the led board side (except the regular one). Phototransistors seem to test fine. Should not do anything to those until we get the right LEDs in.

Brian dropped off LEDs. I put them in the machine.

Couldn’t get infrared camera to turn on but happily phone cameras are also somewhat sensitive to infrared. See pics. LED 5 for trough 4 is dead. I tested the opto sensor on the other side and it is fine.

It would make sense to replace this LED and also the other originals 2 and 3

Ball trough 4 switch is definitely troubled