While writing the simulation software, some of the annunciator lights would stay on after exiting the program. After about 10 minutes of coding, I restarted to check what I just did. Glanced at the panel and the usual annunciator lights were not on. Checked my code to see what I did to mess up the annunciators. Nothing…
Assuming circuit card failure, I got out my meter and logic probe. Nothing, everything tested ok. Ran annunciator diagnostics and noticed a number of the lights were out. Pulled the panel off the annunciator box and checked the bulbs.

Yep – burned out!
Very strange. I had used Christmas tree lights on my first simulator. There I used a 7 vac transformer / full wave bridge / cap to get the DC voltage. It had to be around 5.5 to 6 volts. Never had a failure.

I found some different clear bulbs on Amazon. Also found diodes that handle 10 amps. They have a forward voltage drop of 0.55 volts so if the new bulbs fail, I plan to put one or more diodes in series to drop the 5 volts.

Annunciator problems aside, I have made progress on the software. I have software accessing the majority of the controls/status lights/annunciators (the ones that still turn on…). Have linked into the screen graphic.

Next steps: After fixing the annunciator problem, get the equations into the simulation. After I get normal operations working, start adding events.