SRVO-050 COLLISION ALARM on Fanuc LR mate 200i

  • Hello, I'm Antoine,

    I have a Fanuc LR mate 200i, it was in a warehouse during last 4 years, and 3 months ago, I decide to turn on this machine.

    It was dirty and the main cable was missing (between robot and RJ3 controller) and there was no more battery... but last week after a lot of work it move!

    But it show excessive vibration and throwing frequent SRVO-050 COLLISION DETECT error. It is also emitting a “ratcheting” sound when J2 and J3 is actuated...

    I know this model have breaks on J2 and J3... Is it possible to move with breaks engage? And there is something to do to disable breaks ?

    Please find enclose a video, you will see the SRVO-050 error on J2 and J3 and you will ear the sound... all other axis are OK.

    What should I do?

    Thank you for your help :winking_face:

    Fanuc Lrmate 200i move all axes.mp4

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  • Hello,

    On youtube I find a lot of video which show a Lrmate 200i with no excessive noise and vibration when J2 and J3 are actuated... So mine have a mechanical problem.

    this is an example:

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    Nobody have the mechanical unit manual of this kind of machine?

    I will open it next week and I will try to see what's the problem inside, (is it a good idea?)

    Thank you

    have a nice day.

  • Hello everyone,

    Some news of my dirty poor LR mate:

    I put some grease into J2 and J3 mechanism.. and it made no difference. the same noise...

    last week I opened the case of the robot, execpt some silicone seal it was clean inside. see picture enclose.

    Next week I will control the wiring of brakes. maybe there is a problem and it doesn't works?

    Other Ideas?

  • Like HawkME mentioned you could pull the motor and run it with it disconnected from the robot and then physically move the robot with the motor off and see which one is causing your issue. Since this is something you pulled from a warehouse with dead batteries i'm sure redoing the mastering won't be an issue for you at all.

    "I could tell that my parents hated me. My bath toys were a toaster and a radio."

  • Hello, thank you for your answers.

    I guess, pull the motor and run it without charge seems to be a good idea, but I'm afraid to do it without the mechanical manual.

    I don't know exactly how it's works, what kind of reducer is used inside, and how to dismantle it. Usally in the manual give you an explaination, a procedure and how to dismantle it, with some spécification on bolting torque, or special setting etc..

    If someone knows how this reducer works, it will be helpfull for me.

    Thank again.

  • If the motor seems to run good outside the robot, look at the harmonic drive. Sometimes the bearing-based wave generator will wear enough to cause vibration and give collision alarms. Make sure the correct grease is used. Don't have the 200i manual available where I'm at but the 100i and the 200iB both use Harmonic Grease SK-3.

    Harmonic drives used in many robots are made by Harmonic Drive LLC. A good video to see is at

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  • Thank you,

    I was almost sure it was this kind of reducer, but in fact I think the problem are in relation with brakes.

    On my LR mate 200i there is 2 brakes (on J2 and J3) and only theses axis have problems...

    I thinks wiring of brakes is bad.

    In fact this robot was in a warehouse and someone stole some cable probably for cooper..

    The 2 mains cables between the RJ3 controller and robot was cut (RP & RM cable). I made a DIY cable just to be able to jog the robot and verify all electronics component. And it's works, I can jog the robot, monitoring pulse coder etc..

    But It was very difficult to find all documentation about this cable and maybe I did a mistake on the wiring of brakes.

    It was for this reason I ask on my first post If it "was possible to jog the robot with brakes engage?"

    This morning I did the test : with brakes engage I can jog the robot and It's made no difference.. the same noise in J2 and J3 axis.

    For the test I just disconnect the CN6 plug (on the servo amplifier board)

    So I'm almost sure brakes are engage on my LR mate. But I don't know how to proceed to be sure of this.. any Idea?

    *Sorry for my english I do my best!!

  • In a quiet environment, you should hear a click sound near the motors when the 2 brakes release when you first try to jog the robot.

    Brakes are 90VDC and should measure approximately 1K-1.2K for these small motors.

    Brake connections to the robot base are:

    CN6-A2 > RM-3 > J2 BK+

    CN6-B2 > RM-11 > J3 BK-

    CN6-B7 > RM-4 > J3 BK+

    CN6-A7 > RM-10 > J2 BK-

    To manually check brakes, I use a 60VDC power supply to release Fanuc 90V brakes and it works great every time. Just make sure to secure the robot first.

    At CN6, brake connections are:

  • Thank you for the answer!

    I spend all my week end on this mistake and problem is still here..

    Let me explain what I do exactly and please tell me if it's normal, abnormal or other..

    I only connect brakes wtih 4 wire. Before I have secured the robot to avoid a fall..

    And I connect the power supply but nothing append.. In this configuration I can't jog the robot (normal because motor aren't connected)

    but no "click sound"

    But I have measured electric resistance and it's look like good:

    between RM3-RM10 = 1089 Ohm

    and between RM4 and RM11= 1087 Ohm also.

    So maybe I must connect motor and brakes in the same time? maybe motor activate breakes? is it possible?

    Else, I measure with a voltmeter, tension at CN6 plug, and

    when the power supply is ON, and when I can jog the robot, there is:

    39 V between A1 and A6

    and 53 V between B2 and B7

    What should I do?

    Last thing, I ordered a 60 V power supply, mine is only 24 V maximum..

    Thank you have a good evening.

  • Hello everyone,

    just an idea: there is some option on the teach pendant where I can disable breaks? or configure it?

    Because, this robot was store without battery during 4 years and when I turn it on I did and complete installation from his memory.

    I think this robot is in factory configuration, maybe I need to configure brakes?

    maybe at the starting when I press F1 ans F5?

    What do you think?

  • You should not have to do any reconfiguration and there is no default to return to. If the arm is the same as before, it should be already set for the 2-axis brake.

    At CN6-A2 to -A7 for axis 2, you should measure 100 - 110VDC when the brakes first release. The voltage will then drop to half (50 - 55VDC) after a short period of time. The lower voltage still maintains the brake release and now using half the current. The 53VDC you measured is normal. You should get the same voltage readings for axis 3, CN6-B2 to -B7.


  • Hello, thank you for your help, it's very appreciated.

    I connected as you described earlier:

    A2 on RM3

    A7 on RM10

    B2 on RM11

    B7 on RM4

    And it shows an amelioration!

    Now when I jog the J3 axis I heard just before a click sound from the brake, and J3 axis in one direction (with gravity) move without noise, but in the other direction (against gravity) it moves with the same ratcheting noise as before.

    But when I try to jog J2 only J3 moves and after a short period the TP shows:

    SRVO-036 Disturbance excess (G:1 A:2)


    SRVO-036 Inpos timer over (G:1 A:2)

    On the teach pendant I can monitoring the disturbance torque and I saw the J2 motor reach the limit (12,8) and the axis doesn't move..

    So I think there is a problem in the brake, or in my servo amplifier board..

    Due to Covid -19 restrictions, Amazon delayed the shipping of my 60V power supply.. Maybe I will get it this friday. In this case I will try to release J2 brake manually.

    what do you think about this?

    Last thing I don't sure the arm was the same as before because the seller had a lot of RJ3 controllers and a lot of Lr mate 200i.. maybe he sold me just one of them...

    in all case thank you for your time, I learn a lot of thing and it's really fascinating!

  • Hello, I have just received my 60 V power supply, I will try to release manually J2 brake and move manually this axis and feel if there is no hard point in the mechanism.

    I will do the same for J3... I will tell you.

    Yesterday in an other topic, someone with a similar problem (noise in axis) solve the problem with the wiring of a phase of a motor...

    I will check all RM cable after..

    Have a nice day!

  • After verification, when I release J2 brake, it's very difficult to move J2 axis, when I move it, it's produce a lot of vibrations.. I think the reducer is out of service..

    for J3 axis is the same..

    very bad news..

  • See if the seller will exchange the arm for another. If not:

    Lay the robot on its side (so the grease doesn't pour out), pull axis 2 motor and verify it works outside of the robot. I've seen bad motor bearings act similarly and just because the brakes measure good and give a mechanical sound does not mean it is mechanically disengaging.

    When the motor is pulled, you can assess the grease and the wave generator. If the grease is black and runny, it is not a good sign. If you clean the wave generator, you need to lube it to get a good feel for wear as even a new one will feel 'rough' without being lubed. The teeth on the flexspline should still have a little bit of a flat at the top and not be worn till they're pointed. Seen flexsplines damaged by collision and shipping damage where the flexspline is twisted somewhat and causing issues.

  • Thank you very much,

    I will pull out the J2 axis motor.

    But first I will study maintenance manual of the Lr mate 100i and 200iC ans 200iD, I will compare and I hope it will be the same for the lr mate 200i.

    I think it will give me a better idea of the procedure and all tools needed.

    and of course I will post photos.

    Have a nice day!

  • Hello,

    Since yesterday, I read a lot of documents and I have few questions before pull the motor.

    -After that I must to do a mastering of this axis? just to be sure, no special tools are needed?

    because I think I already did a mastering on this robot, because when I change dead battery, the TP show me and error message " robot must be calibrated" or something like that, and a BZAL error, I only reset pulse coder alarm, and jog the robot to the zero position (witness marks) and just click on "Zero position master" and It was OK. After pull the J2 motor I will redo the same?

    -When I pull the J2 motor I will see the wave generator, but I'm afraid of one thing: reassembly. Is it complicated to put the wave generator into the flexspline?

    -And last, just to be sure: I will unscrew bolts marked A (see enclose) and pull the motor, what's happening if I unscrew bolt marked C? of course I will lay and secure the robot, but maybe I will see bearing under? Or it's not located on this side?

    Sorry, I have a lot of questions , but I never did that kind of work, I have already dismantle many engine or other thing but never a harmonic drive or an industrial robot.. So I'm a little bit afraid, but I want to learn, it's the only reason why I bought this machine!

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