FANUC A05B-2490 Deadman Switch Replacement Work-Around

    Good afternoon everybody,

    We have a strange problem with our teach pendant and require some assistance with diagnosing what went wrong. We got a single chain fault error that was caused by the Deadman switches on the back of our teach pendant not working anymore. This is the original teach pendant from when the robot was integrated in ~2005 so it's not outside the realm of possibilities. We attempted to hook up a work-around with a 2-position microswitch (see images) while we waited for replacement switches to arrive but it seems to have made the teach pendant unusable when we attempted to use it with the microswitch work-around. Prior to us trying this work-around the teach pendant would turn on when plugged back in using the wire from the controller even if both deadman switches were disconnected I believe. Now the teach pendant doesn't turn on at all and we're afraid that we might have cooked something on the main board and it's more broken than it was before. Any assistance with this matter would be greatly appreciated, thanks!


    Edit: If this information is useful we have a Rj3iB controller and a m-16iB arm.

    Edited once, last by rpgemployee (June 25, 2024 at 9:43 PM).

    You should have used a double-pole switch. The Idec switch you removed has 2 sets of contacts, one set of contacts for the 24V chain and the other contacts for the 0V chain. Your switch looks the 24T & 0V may be shorted together.

    The simplified block diagram from the manual only shows one of the deadman handles with its Idec switch and it's two sets of contacts, 24T & 0V.

    Seems to me you could have left the wires at the faulty switch open and used the other deadman until the new switch arrived.

    Prior to us attempting to find a work-around it seemed like both Deadman switches were broken due to wear and tear. We think one of them broke a while ago which happened to be the one we didn't use as much so we didn't notice until the other broke as well. Is the teach pendant bricked or is this something we can recover from? Thanks for the help!

    If you had ordered the correct switches, I would install them and see if it worked.

    Switch only is Idec part # HE2B-M200
    Switch only with yellow boot is Idec part # HE2B-M200PY
    Switch with harness is Fanuc part # A05B-2490-D003

    Even if pendant still doesn't function, you may want to consider having it repaired or see if someone offers an exchange.

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