Fanuc RJ3IB help

  • Hi we have a Fanuc RJ3IB and the problem we are having it only starts in controlled start and then we have to do a cold start for it to boot normal. We tried changing the teach pendent, cable and CPU but are having no luck. Anyone have any ideas on what else to check? We would like the controller to boot normally. thanks in advance. Seems like it is stuck in a controlled start loop. I know after it boots up in controlled start then if you choose "start cold" then that breaks the loop. This is not the case here and everytime the controller is restarted it goes back to controlled start all over again

    Edited 2 times, last by duf1 ().

  • duf1

    Changed the title of the thread from “Fanuc RJ3IB” to “Fanuc RJ3IB help”.
  • After the controlled start and then cold start. It runs fine until we reboot it and then it boots right back into controlled start. During the controlled start and the cold start process the controller is not turned off

  • One of my questions would be:

    1. At what point did this start occurring - what events lead upto this for this to 'suddenly' happen.


    I came across the following thread and the last responder #6 was referencing a variable that required altering to cure their controlled start loop.

    Controlled Start Loop


    Maybe worth having a look at that.

  • Thanks, I seen that article before I made my post and that is not it. Not sure when it exactly started since we have three shifts here. But more than once a few personal restarted the controller and it boot to controlled start and chose the INIT option for startup. I then thought maybe we had a problem with the CPU and that may have been causing the controller to stay in the controlled start loop. So I changed the cpu and it also continued to boot into controlled start. I took the original cpu and put it into a spare controller and it booted up normally. Also swapped the power supply. Stumped here on this one and there is not to much left besides the safety circuit etc

  • Sounds a little strange...….I sense pixies are at work.

    Have you seen the following thread too, there's a couple of other methods for cold start:

    Problems after control start


    I know it's applicable for a different controller, but worth a try.....

  • On those old controllers if USER1 and USER2 buttons on the SOP get dirty and fail closed, the controller would boot like when PREV and NEXT are pressed on the TP, straight to the boot menu and to controlled/init start selection...

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