Have had some weirdness with optos lately on an NBAFB and narrowed down to 7-opto board. Ordered a replacement, installed today. Went into switch edge test and one ramp opto wasn’t working. #7 on the board. No glow on the transmitter with camera. All others ok (5 in trough #1-5 on board and #6 another ramp). Thought maybe new board had an issue or maybe opto just gave up. It happens. So I flip-flopped with the other ramp opto set that’s on #6 since they have molex connectors so easy to swap to see if it followed transmitter or stayed with #7 location. After turning back on neither worked at either location. Like being on #7 blew them. All the trough optos transmitters are 1.4v but these two are 12v measuring at transmitters. Don't know if that is normal. Receivers work with flashlight test. So now I have two dead optos. Grabbing some more tomorrow locally but worried what will happen. Put old board in and measurements are all the same. With the old board all optos worked but was getting phantom closures. Not sure what I can check to make sure everything is ok before connecting and blowing more out.
New! Dark mode!
Browsing Pinside at night? Getting tired of all the white? Switch to dark mode using the button in the top right (or CTRL-B)!