Polar 76 EM Back Gauge Position Display never comes on

Discussion in 'Cutters and Trimmers' started by James Edgar Marcus, Nov 6, 2019.

  1. James Edgar Marcus

    James Edgar Marcus New Member

    Joined:
    Nov 2019
    Messages:
    1
    Location:
    Marion, OH
    I am new at this and operating a Polar 76 EM.
    Just got a used cutter and tried to get it to work.
    When I turn on the Back Gauge Position Display never comes on.
    Therefore cutter does not work. Any Ideas?
    Thanks
     
  2. CHOCK

    CHOCK Senior Member

    Joined:
    Dec 2016
    Messages:
    2,852
    Location:
    Managua,Nicaragua
    Hi sir:
    Hope you are well.
    If i believe that you are trying to say, that display is NOT turn ON?, you must measure the voltage display Keyboard: +9Vdc, tolerance 8.4-9.6 Vdc measure with a Good DMM.
    Check in the board BT: jack BT 1-2
     
  3. dave weiser

    dave weiser Member

    Joined:
    Oct 2019
    Messages:
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    Location:
    7404 Talbert Ave Huntington Beach Ca
    Hi i have similar problem on at 1990 Polar 76em.
    everything works but no LED lights on.
    it finds home, its makes cuts, i can change sizes on keyboard and its accurate.
    i deleted all cuts in program 2, i made a program at 10", 8" and 6" then went to auto and it runs the program. Just no LED lights or any display on???

    i checked voltages 5V and 9V on red voltage check points and all is good.

    what part on BT board tells the lights/display to come on after home search is found at start up??

    i have a second Polar 76em cutter in my shop. i pulled the display off this cutter and installed in non working display cutter and everything lights up and works perfectly.

    so problem has to be on the BT board on cutter 1 a
    ANY HELP OR DIRECTION WILL BE MUCH APPRECIATED Thank You all in advance!!! Dave
     
  4. CHOCK

    CHOCK Senior Member

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    Location:
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    Hi sir;

    I am recommend to reheating the complete electronic boar, for cold+dry solder joint carefully, many frequently in electronic problems

    Let me know, sincerely

     
  5. dave weiser

    dave weiser Member

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    Messages:
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    Location:
    7404 Talbert Ave Huntington Beach Ca
    Thank you for your reply. We will try that 1st definitely, these boards are nearly 30 years old now. Does D7 control all the led's?
     
  6. CHOCK

    CHOCK Senior Member

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    Not sure, but anyway you can test it.

    Proceed as I did indicated you before

     
  7. Nguewa

    Nguewa New Member

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    Mar 2022
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    Location:
    Yaounde
    Hi every one!
    New in this forum, and i Hope to feel at home

    I have an error 64 on my polar 76Em.

    Any help would be appreciated. Thanks in advance
     
  8. CHOCK

    CHOCK Senior Member

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    Location:
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    Hi, sir Welcome to the Forum

    Would you please tell me, what the exactly problem, in order to help you?

    Blessings
     
  9. Nguewa

    Nguewa New Member

    Joined:
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    Location:
    Yaounde
    Thanks for your intérest
    In fact, thé problème is that, the starting process of thé machine does not go to the end. It shows 64 code when the table stops
     

  10. CHOCK

    CHOCK Senior Member

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    Messages:
    2,852
    Location:
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    Hi sir:

    1)Please measure the Regulated Power supply for < 1) +5Vdc 2) +24Vdc the tolerance must be 0.7% up or down, send me Pic for both.

    1a) measure the limit switchs for forward or backward : s10 +s14 for open, or faulty, or loose wires, repair, or replace it.

    2) if the voltges are o.k, Reset overload switch Q96 , and test if there 3 phases in the input of terminal of Q96, and then in the output, tight very well the cables, and look for oxidation, or broken, or interruption.

    3) if everything is o.k with steps #2, measure the input in terminals of the backgauge motor, if there 3 phases, if there and the motor NOT Run, look for the Cluch of motor, if there are NOT voltage in the terminals of motor, the problem will be the Q96, adjust it, clean it , or repair, or replace it.

     
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