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  1. #1

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    Nov 2012
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    Unhappy Fanuc 400 Servo alarm

    6M controller, (Matsuura 760 VDC) with a 400 Servo alarm. Called Fanuc and the response was so vague, "Could be anything" they said. No alarms on drives, swapped all the top cards and base units, cables all intact, megging the servo motors now but they seem fine. Cannot figure this one out. 30 years in the business, I love my Fanucs, but this one is kicking my tail! Any ideas out there? (also a 4th axis on machine, Tsudokomo) Thanks so much.

  2. #2

    Join Date
    Feb 2011
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    555
    what servo drives- 6045 DC/scr, 6047 DC pwm, or 6050 AC?

  3. #3

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    Feb 2011
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    when swapping top cards(assuming 6047 or 6050) watch the jumpers...usually only one drive has 5 wires going into the white CN1 plug, the one with 5 wires S1 jumper gets set low, the others with 3 wires S1 must be high(S1 just bridges the 2 extra wires that come from NC thermostat(s) in transformer/regen module). if S1 is low without those wires, you get 400...with the wires, pull the plug, check ohms across the 4/5 wires, should be shorted.

    on the feedback plugs on the motherboard, check ohms across pins 8/9, thats where these wind up, all 4 axes should show continuity between pins 8/9 on the pulsecoder cables...if not the thermostat on the drive heatsink or the thermostat under the motor cap might be open. non-ABS encoders send the thermostat signals out of the motor on pins R/S, you can pull the plug, check there too if found open at the control, just to verify if cable or thermostat is issue.
    if thermostats check OK, I think there is a thermostat on the motherboard too- thought it gave a 'locker overheat' alarm, but dunno, been a long time...might give a 400...that thermostat is usually a 1-1/2 inch long silver tube shaped thing with red ends/single axial leads, have had a couple of those fail- again just check continuity.

    400 should be easier than 401- those can be anything

  4. #4

    Join Date
    Oct 2009
    Posts
    190
    This is an overload alarm. It could be one of the servounits.
    Power off the machine.
    Check in the back of the servounits a thermal relay (it has a white button). Try to push it.
    Regards
    Alex

  5. #5

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    Nov 2012
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    6047's

    Servos are 10MB, Drive units are A06B 6047's. (Sorry) and thanks for the replys!

    Dan

  6. #6

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    First thing I tried, nope. Thanks

  7. #7

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    [QUOTE=tc429;1202213]when swapping top cards(assuming 6047 or 6050) watch the jumpers...usually only one drive has 5 wires going into the white CN1 plug, the one with 5 wires S1 jumper gets set low, the others with 3 wires S1 must be high(S1 just bridges the 2 extra wires that come from NC thermostat(s) in transformer/regen module). if S1 is low without those wires, you get 400...with the wires, pull the plug, check ohms across the 4/5 wires, should be shorted.

    on the feedback plugs on the motherboard, check ohms across pins 8/9, thats where these wind up, all 4 axes should show continuity between pins 8/9 on the pulsecoder cables...if not the thermostat on the drive heatsink or the thermostat under the motor cap might be open. non-ABS encoders send the thermostat signals out of the motor on pins R/S, you can pull the plug, check there too if found open at the control, just to verify if cable or thermostat is issue.
    if thermostats check OK, I think there is a thermostat on the motherboard too- thought it gave a 'locker overheat' alarm, but dunno, been a long time...might give a 400...that thermostat is usually a 1-1/2 inch long silver tube shaped thing with red ends/single axial leads, have had a couple of those fail- again just check continuity.

    400 should be easier than 401- those can be anything [/QUOTE

    Ok thanks! All R/S at motor are closed, Thermostat on board is open. 4/5 is shorted, and pins 8/9 on all cables are closed with exception of the 4th which is open. Thanks!

  8. #8

    Join Date
    Apr 2005
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    163
    After checking what chip34 has stated and repaired problem , you might have to "while turning on typing P, Q, cancel" to cancel alarm code. I have found that on this old control, even when you have corrected the problem, you have to reset.

  9. #9

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    Quote Originally Posted by John Bennett View Post
    After checking what chip34 has stated and repaired problem , you might have to "while turning on typing P, Q, cancel" to cancel alarm code. I have found that on this old control, even when you have corrected the problem, you have to reset.
    REALLY??? Never heard of that one.

  10. #10

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    Fourth axis plug is shot, repairing it now, but I turned the parameter for the fourth "off" and still have 400 servo alarm. Not sure that is the problem. This is maddening.....

  11. #11

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    Feb 2011
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    Quote Originally Posted by chip34 View Post
    Fourth axis plug is shot, repairing it now, but I turned the parameter for the fourth "off" and still have 400 servo alarm. Not sure that is the problem. This is maddening.....
    4th is on addl axis card, it has its own jumpers for transformer overheat/ disconnection. Turning off the axis won't bypass the thermostat, gotta move the jumper-I think


    Is this a 6 or 6b2? Old 6 had a boatload of EPROMs across top of master board, "level up" or B2 version has a separate rom card with all the system EPROMs...I've got dwgs for B2, but not the older ones...

    Thermostats should all be closed- you mentioned one was open? Try jumping across it.

    *If* the 6047 drives have them ( i dont remember) verify the little tiny clear fuse on the upper left part of the drive topcards on each drive is good, my eyes are so bad I can't even see the filaments anymore, gotta unplug/meter them
    Tim

  12. #12

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    Feb 2011
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    Quote Originally Posted by chip34
    R/S at motor are closed, Thermostat on board is open. 4/5 is shorted, and pins 8/9 on all cables are closed with exception of the 4th which is open. Thanks!
    Oops, just reread your reply, that 8-9 on your 4th should be your problem- turning off params won't bypass it... Bet you got it now

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