1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

Terex TB42

Discussion in 'Forklifts/Telehandlers' started by telwood, Jun 27, 2020.

  1. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    123
    Location:
    GA
    I own a Terex TB42 boom lift. Gas motor etc. Everything works great but last week I lost forward drive and the high speed function. I've read the other post and realize these things can be a pain.

    So I bought it from a dealer and called them to do a site service call a couple weeks ago. Called them back the other day and they pretty much whined saying their Optimizer 4 must not be working because the motor shut down every time they hooked it up. It seems like they would still be able to troubleshoot based on just not going in forward and the high speed toggle. The tech said he thinks it is wiring because the drive motors rarely go bad....who knows but I got no answers that have fixed it.

    I played with it some today just checking connections and it seems to only drive backwards no matter which direction I move the joystick. The high/low toggle does nothing as it just stays in low speed.

    Logically it seems the speed toggle must be bad and maybe the joystick? But reading about all these OEM Controls I am a bit lost what to do next. I plan to call them Monday and others and start trying to figure this out but hoped someone could enlighten me with the possible troubleshooting? All controls except those 2 work perfect.....it can't be moved from the bottom controls so I am referring to the basket controls. Wheels steer fine and all boom actions are good.

    Any opinions would be appreciated,
    Tom
     
  2. barklee

    barklee Senior Member

    Joined:
    Aug 4, 2009
    Messages:
    903
    Location:
    ohio
    Does that have the superflex circuit board in the lower control panel? We have had a few go bad and they will do some crazy and scary stuff. I would check that out.
     
  3. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    123
    Location:
    GA
    Yes, I am working with OEM to diagnose the Superflex board. Apparently they can be sent in for rebuild but am trying some other things first that may be the culprit
     
  4. barklee

    barklee Senior Member

    Joined:
    Aug 4, 2009
    Messages:
    903
    Location:
    ohio
    I noticed if you press your finger on the board while using the function that doesn't work it will start working if the board is bad. Try that out.
     
    mikebramel likes this.
  5. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    123
    Location:
    GA
    I'll give it a try...couldn't hurt.
     
  6. skata

    skata Senior Member

    Joined:
    May 10, 2007
    Messages:
    1,391
    Location:
    midwest
    Bad solder joint?
     
  7. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    123
    Location:
    GA
    Just to follow up for anyone with this equipment. I chose to call a dealer and that was a waste of time as they sent a tech and fixed nothing. I did the research and figured out how this thing works. More time that I'll admit to but probably the best way owning older equipment.

    The forward and reverse was fairly easy to diagnose as it has a device called a digi-sensor attached to the base of the steering/forward reverse control joystick. An LED light comes in both forward and reverse setting if it is working properly.

    In my case the LED for forward wasn't lighting on my unit so the digi-sensor is bad and needed replacing.

    A great source for electronic parts is Hindley Electronics. They seem to have parts for Terex, Genie, Skyjack.
     
    BigWrench55 and skata like this.
  8. telwood

    telwood Well-Known Member

    Joined:
    Mar 20, 2013
    Messages:
    123
    Location:
    GA
    Changed out the digi-sensor and machine run great in forward and reverse. $169 part and about half an hour labor.