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.