Electical Problems with Jingong Gearbox

[mmmken]

Hello all,

I'm very new with airsoft and I seem to have the worst luck with it for some reason.

This is the gearbox I have: http://airsoftdepot.ca/catalog/produ...products_id=33

My gun had problems shooting on Semi-Auto and could only shoot (without problems) on Auto. I contacted the original owner and he told me that it is a common problem on the gearbox I have. It is rear-wired for LiPo in the buffer tube. One day it stopped firing, and I found that it was the wiring in the buffer tube to be at fault. Basically the thin red wire that connected to the blue/black shrink-tubed thing (is this the MOSFET?) came loose from the solder. I re soldered it back, and it started to work again on Auto.

I tried testing it on Semi-Auto, and it shot once - but failed to shoot again. I recheck the solder and it seems fine. I've taken apart the gun to inspect wiring, but I don't see anything wrong.

Any ideas? I can pay for a gundoc to have this fixed as well (in Toronto/Markham).

[HKGhost]

Your switch assembly contacts could be fried or has a build up of carbon, which will cause problems on semi.

[mmmken]

I had someone tell me that my switch or tappet plate is broken.

In that case, wouldn't Auto work right now?

Nothing at all is working though. As for the assembly contacts, are you talking about the two bronze/brown rectangular plates (that touch when off safety), or the circular ones that aren't really touching anything? Can this be repaired as simple as wiping it clean or what?

And thanks!

[HKGhost]

The switch plate could be the problem as it may not be in the right position when on semi. To fix that, you'll need either a different switch plate or a different fire selector. You might need to play around with that. If tappet plate is the cause, your gun won't fire at all. The two copper prong and the part that moves between them is my guess of your problem. You just need to clean them up with fine sand paper or steel wool. This will fix the problem but it will happen again. A mosfet will fix it for good.

[mmmken]

The gun does not fire at all anymore though. Could this be the tappet plate?

[DoctorBadVibez]

Make sure that the shrink film is still on all metal parts so that there is no short?
Make sure that the connector tabs on the motor are secure, this is a major "derp" thing, trust me, I've had that happen to me.

Your tappet plate is what brings the nozzle in front of the gearbox back to allow a bb to chamber before it fires. If the tappet plate was the only issue your gearbox when in the gun, would only dry fire. If its your switch within the gearbox itself, thats an easy fix, just clean contacts and reassemble gearbox.

If you really want to check your electronics, you can by dropping out the motor plate on the pistol grip and pulling the motor down so it won't engage the gears and see if the motor rotates when you pull the trigger. IF you fear broken parts inside, do NOT try to fire the gun any further as you run the risk of grinding parts inside or overloading your electrical system simply because nothing is moving because parts might be wedged inside.

PS, if the semi and auto firing issues were normal with Jing Gong gearboxes, they wouldn't sell for a dime.

[mmmken]

Hi everybody,

I took apart the gearbox today and I have an idea that it was indeed the switch plate not working properly. I replaced it with a new one and it is working now in addition to a new mosfet (which may have been blown). Thanks for all the help everyone!

Kenneth