JG/GE/LT M16A3 won't fire.

Discussion in 'Gun Building, Modifications & Repairs' started by Dead_Christmas, Apr 18, 2021.

  1. Dead_Christmas

    Dead_Christmas Active Member

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    Hello,

    I have an LT-22B M16A4 from JG/GE that refuses to fire. How I mean is that the motor works until it tries meshing its gear with the connecting gear in the GB. I'm stumped. I have the wires on the appropriate tabs, running through the correct way, and again, it completely works fine outside until it tries moving the GB. 11.1 LiPo. Nothing, looks completely frozen.

    Any help is much appreciated.
     
    Last edited: Apr 18, 2021
  2. danerd

    danerd Well-Known Member

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    When pulling the trigger, does the gun make a clicking noise at all, or is there no response whatsoever?
     

  3. Dead_Christmas

    Dead_Christmas Active Member

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    It tries to work the gears, but it sounds like the motor height is completely off no matter where I put it. If I go too deep, it just flat out stops spinning, and there's no clicking sound. The motor is completely functional as it seems.
     
  4. danerd

    danerd Well-Known Member

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    Which way are you running the wires inside the grip? I have had instances where if I routed the wires a certain way in the grip, they would throw off the motor alignment and mess up other things as well.

    Just trying to eliminate the simple things first.
     
  5. Dead_Christmas

    Dead_Christmas Active Member

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    I've got them running through alongside the rear of the pistol grip. Next to the textured side.
    I was doing a video of the repair, and made sure to double check to how the video showed them upon first revealing.



    I will try using the 11.1 next time as well. Surely that's more than enough power for a stock gun?

    Another note worth mentioning is that this was a boneyard gun. Maybe the motor wasn't installed correctly by the previous owner? I had a blow green blade fuse that I bypassed and that got the motor working, but it still isn't functional entirely.
     
  6. danerd

    danerd Well-Known Member

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    Im assuming the motor is the one that came with the rifle? It may be a bad motor or a gearbox issue being that the unit is/was a boneyard item to begin with.

    So far we have checked:
    - Motor works outside of gearbox while under no load
    - routing of wiring within grip
    -motor tabs are in good working order

    For giggles, swap the polarity of the motor leads. It may be the motor was assembled wrong from the factory and the endbell is reversed. If you have another good working motor on hand, try using that to rule out the included one. If that doesnt work, you may want to crack open the gearbox and check for issues there.
     
  7. gunnerk19

    gunnerk19 Active Member

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    Is the anti-reversal latch stuck maybe?
     
  8. Dead_Christmas

    Dead_Christmas Active Member

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    I have no idea how to check for ARL jamming. The last thing I want to do is open up the GB itself. I'm afraid that I don't have the knowledge, experience, and skill to do so.

    Danerd, I will try your fixes. I think that the blown fuse can indicate something similar to a jam, possibly? Might be a helpful clue.
     
  9. Dead_Christmas

    Dead_Christmas Active Member

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    OK, upon further testing as recommended. The wire polarity is not reversed. Closer attention reveals that it just makes a clicking sound when ran with a known good 11.1 LiPo. It sounds like the GB/Motor is trying to work, but something is obstructing it, possibly the ARL as gunnerk19 suggested.

    Is there any way I can de-lock, or at least check to see if the ARL is active with this GB without taking it apart? I swear to god, it'll be a death sentence to this copy if I take the GB apart. I just can't do it on anything but a V3.
     
  10. Peeque

    Peeque Well-Known Member Supporting Member

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    Some gearboxes have a little cut out on the top or bottom shell in line with the ARL for easy access.

    If yours has that, push it towards the motor hole with something like a screw driver. This will allow the gears to spin backwards and reset.

    If it doesn't have those slots you'll need to look into the motor hole. With the gearbox facing to your right, the ARL will be on the left side.

    You will probably need to use a screw driver to rotate the bevel gear counter clockwise just a bit to remove pressure off the ARL. At the same time you will need to pull the ARL towards you and remove the screw driver so the gears can spin backwards and reset. It's a tricky to do without three arms.
     
    Last edited: Apr 18, 2021
  11. aotsukisho

    aotsukisho Well-Known Member

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    I would test with a different motor, even a properly functioning stock motor on 11.1v should 'break' the seize condition being fired on full auto, assuming nothing inside is actually damaged. "Spins under power with no load" does not necessarily mean "functional".

    Blowing fuses usually points to a short, whether it be a coil on the motor armature or somewhere in the wiring along the way.

    ARL unsticking can be done without removing the gearbox from the receiver. Remove the motor grip, and use something like a paperclip with the end bent into a short L to reach over and pull the flat face of the ARL down
     
  12. Dead_Christmas

    Dead_Christmas Active Member

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    OK, sorry for the late response, but I pulled a confirmed working G&P M120 High Speed motor from a G&P i5 M4A1 (Super-regret-purchase).

    [​IMG]

    Tried it all four ways, both polarity hook up positions, and while it spins, it cannot move the pinion(?) gear.

    I think the GB itself, as we feared, is the culprit. I'm going to try the suggested moves to possibly unlock the GB from the ARL.

    OK, I cannot seem to unlock the ARL. Would opening the GB allow me to fix it? I have a ball magnet that I can use to hold it in place and make things a lot easier for me.
     
    Last edited: Apr 18, 2021
  13. Dead_Christmas

    Dead_Christmas Active Member

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    Yeah that damn ARL is stuck good. Tried at it for about half an hour with several different tools, paper clips and all, and can't get it to reset and spin.
     
  14. Peeque

    Peeque Well-Known Member Supporting Member

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    You need to relieve the pressure on the ARL from the bevel gear by turning it by hand. You will need to use a screw driver or some kind of metal rod to get enough leverage.
     
  15. Dead_Christmas

    Dead_Christmas Active Member

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    I just had a motor connector break off from the wiring...I'll just work up the balls and get the whole damn thing apart, and pay attention to getting it back together. Gonna have to re-solder the wires and ****...I'll see what I can see and update when I make any progress, if at all.

    What would cause a short in a stock gun? I assume it's from the insulation in the wires, but how on earth would that happen? I think the copy may have been modified unsuccessfully at some point.
     
  16. Peeque

    Peeque Well-Known Member Supporting Member

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    If you try to take the gearbox apart before pulling the ARL and letting the spring decompress it's gonna blow up when you go to lift the top shell off. Then you will have no reference on how it looked before which will make reassembly even more difficult for your first time.

    As for the short - I don't know.
     
  17. Dead_Christmas

    Dead_Christmas Active Member

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    I think that, gathering information from videos and images, I should be able to at least bang some rocks together and give it a whirl. I have a CYMA/Cybergun M4A1 that I can try hooking up the M16A4 external bits to if the **** hits the fan.

    It'd be awesome to fix this copy. It'd be the first V2 that I'd ever successfully repaired.
     
  18. Peeque

    Peeque Well-Known Member Supporting Member

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    I think you said you've worked on a V.3 before?

    The V.2 is very similar looking inside to the V.3. So you shouldn't have too much trouble.
     
  19. Dead_Christmas

    Dead_Christmas Active Member

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    Indeed! I was able to successfully reassembly at least one AK gearbox in my lifetime. I'm just absolutely **** at soldering and figuring out how to route wires.

    Thanks for the faith.
     
    Peeque likes this.
  20. Guges Mk3

    Guges Mk3 Administrator Staff Member Administrator Supporting Member Lifetime Supporter

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    If you work on mechboxes...you need tools like this too.

    [​IMG]

    Tool second from the laft can get any ARL unstuck with out opening the box.

    Use proper tools for the job...not paper clips...