Tool magazine keeps rotating!

Hi Guys.

I have a problem with my YAM MV 3 A with Fanuc 0M.

Out of the blue after i started it up the other day, the tool magazine just keeps rotating, when i call a tool. No alarms No nothing.

All the sensors in the magazine lights up,when the tool pocket passes them but i seems like the controller dosen´t get the signal?

Anybody that had this error before or somthing like this?


I can execute a M6 if i don´t call a tool, an i just grabs and changes the one that is in position, but as soon as i call a random tool from the magazine, it just keeps rotation... can´t stop it, only emegency stop can make it stop.


Hope i guys have som good ideas, to what the problem is.


Kind regards Martin

I have seen sensors light but not pass the signal to the I/O. You will need to look up the inputs and verify that each one is working. The ladder is poorly written as to why you don't have any alarms.

Yes, tomorrow we will messure if the signal arrives on the connection plug og the I/0 board. The odd thing is, that it actually need to be both counter signals that has to be cut off.....otherwise the control will make an alarm because the count is wrong, and that seems very unlikely, since the machine hasn´t been mooved or anything. And there is 24 v in to the sensor, and they are tested when the machine is turned off, so they are not burned to short circuit.


Do you know, about other things that can affect that the signal or controller does not acknowledge the signal or something like that? So the fault lies another place but affects this signal/function?

The I/O board that the signals go to. I would check the Diagnostic page to see if the controller is seeing it.

Hi Guys.

After alot of troubleshooting and a CNC repairguy missed it, i found 2 cables that a mice had chewed over:mad: The worst thing, was that the CNC guys, had beed ind that installation, and did not see it, tho it was the first thing you could see, when the lid came off.

So 2 solderings later, the machine was running again.


Regards Martin