Guys, great information thanks.

When i compared them, the only visible difference was the diode was missing the polarity stripe, if it was a jumper, the insulation looked very similar to a diode, and i recall there was a solid jumper wire on the opposite side of the pb from the diode. It was clearly for a hall pushbutton, which has a seperate interface to the controller.

If you forget about the oopsy for a minute and go back to the beginning...
When i swapped the existing pushbutton around to see if it would work on another floor input, the 3rd landing still wouldn't latch a call, even with a different assembly. Has anyone lost a car call input before in a similar way and replaced the input chips or entire board as a fix?

Also, i have an LRV4 board in stock, whats involved with the upgrade?