Hello everyone, I recently purchased a used 2004 CNC 3 axes mill and it worked fine, then one day I got some "tank coolant HI" message and upon inspecting the sensor and its output I figured my PMC/PLC won't reckognize the input.

My jog functions don't work (altho they glow up and beep) and my EMG STOP button doesn't work either. When looking at ladder diagram in my PMC diagnostic screen when I press the EMG stop the line doesn't glow up as if it is not reading inputs correctly. Switches and sensors are okay and voltages are okay everywhere (24V). As I own another exact same machine I swapped fanuc input cards and nothing. I am affraid to swap further the cards with batteries as they contain parameters and other data I don't want to mess up. Can someone help me diagnose the problem?

I have attached a photo of ladder diagram in question. Can provide more photos and information if someone can guide me throu diagonstic steps.

Thanks for reading, Izidor