[ARJMFG]

Hello, I run a SNK bridge mill with a fanuc controller, and out of the blue it wont change tools when running a program. the first tool will run, but whenever it goes to do the tool change for the second tool it goes up to the reference point indexes the spindle brings the next tool out, and then throws a p\s 0194 alarm stating zero return point not on reference? I then have to manually remove the tool from the spindle and atc arm and clear the memory, shut down the machine, power it back up and re home it, once this is done it will do a tool change in MDI mode no problem. I am still pretty green when it comes to a lot of this, but i have checked my post processor, and old programs that i have ran on the machine before, and everything along those lines has not changed. I have read for solutions on the internet and am all out of ideas on what to check next. any help would be greatly appreciated.

[fordav11]

possibly ref return switch is stuck or bad?

[ARJMFG]

possibly ref return switch is stuck or bad?

Thats what I was thinking at first, but if a return switch were bad would it still do the tool change in mdi?