G3 Problem

Hello, AC Man here.

So, my JG G3 broke a couple months ago. It broke about 5 minutes into the first round of the biggest game I had attended (which is about 8-10 people..) and I was wondering if any of you guys could help me diagnose it. So... Here's what happened:

First Round: Got together with my group of people and ran to take cover in a base, when we got there we opened fire on the enemy. I shot about 6 times on Semi-auto and then turned to full auto for a little bit. then switching back to semi-auto it was still firing full auto when I pulled the trigger. I turned it to safety and then turned it back to semi. While in semi-auto it fired constantly on full auto without me pulling the trigger. it only stopped when I put it on safe. I tried to take the battery out and put it back in, but the problem remained. after a while when I switched to semi and full auto, it just wouldn't fire at all. So I took it in to the house nearby and started stripping it, thinking it was a tappet plate or selector switch problem. I took it apart, checked the selector switch and tappet plate (note: I didn't take apart the gearbox completely, for fear of breaking it more) and saw if I could improve anything. Afterwards, I greased it up, and put back together, but it still wouldn't fire. Also there is no noise heard from the inside when the trigger is pulled, which lead to think that maybe it was the motor, which had stopped working since I didn't have a good fuse in the wiring, but the motor was not hot, which has led me to think that the wiring may just have a short somewhere inside the gun, or inside the gearbox. I will be taking my gun apart shortly after I post this, and if you respond in time, I will diagnose it and reply back to you in the most timely manner I can.

Thanks in advance,
Accordion Kid.

To me it sounds like a stripped gear, as well as a problem with the selector switch. I'd make sure to check the whole thing over, but as long as you know what your doing, breaking the Gearbox open is probably the best thing you can do right now. If nothing's wrong in there, then it's probably an issue somewhere in the wiring.

Ok, I've pretty much eliminated most problems except for the possibility of faulty wiring, but so far the most likely problem is inside the gearbox.

SO.... anyone know what kind of screws are on the JG V.2 Gearbox? Because I can't get it open. Also, thinking about this, if it was a broken gear tooth, or a broken piston tooth, wouldn't I be able to hear the motor trying to do something?

BTW, if someone could reply before 10 P.M. pacific time, they'd be a hero.

Alright, after rereading what you said, this is my theory:
Inside somewhere, two wires were rubbed, causing a short circut. This short circut caused a continuous run of electricity to the battery, which caused the replica to fire uncontrolably on full auto until cutting the circut with the Safety on the selector switch. This short also drained your battery quickly so it would no longer fire, or it cut the circut completely. This could have happened inside the gearbox, but I would look around too. A possible thing to check would be the fuse, because if it did short out, it was probably running lots of juice through.
Hope I helped a bit. Again though, it's just a theory.

@alexkmmll
First, the battery was not drained, I tested it on another gun.
Second, the fuse was blown before this incident. The fuse was wrapped with aluminum foil, because I'm too cheap to buy a new fuse, but I will be ordering one eventually.

I am planning on looking inside the gearbox, I just need to find what screws are in it first so i can open it up. Thanks for the theory BTW, it helped alot.

Accordion man wrote:

@alexkmmll
Second, the fuse was blown before this incident. The fuse was wrapped with aluminum foil, because I'm too cheap to buy a new fuse, but I will be ordering one eventually.

Bingo. Get a proper fuse. This should have been a red flag at the beginning. Aluminum foil has many impurities and I am almost positive that this is what's causing these problems. Aluminum is not a great conductor (Compared to Copper) and aluminum foil is thin, flimsy, and wont hold up long (as well as being dangerous). Try replacing it with a proper fuse and inspecting the area around the fuse box for any wear on the insulation of wires, or misplaced wiring.

However, we connected the two sides of the wire, bypassing the fuse, and nothing happened. Also I had been using the aluminum foil for about 3 months before.

You may have burnt out the motor because of the lack of a fuse. Too much power to a motor will cause it to burn out like that. Try pulling the motor out and run it directly by bypassing everything else. If it doesnt work, well then you know your problem, now don\'t you?

I have already bypassed everything to the motor.

It worked fine.

Was the pinion gear still attached to the motor? And were you hearing any grinding inside the gearbox? Is the motor running at all when your pressing the trigger?

If the pinion gear is not attached to the motor:
It is not linking with the gearbox. If it is, try ajusting the height just to make sure it's interlocking with the other gear.

If your hearing grinding:
You've stripped a gear.

If the motor's running but nothing's happening:
You've stripped a gear.

If the motor isn\'t running when you press the trigger:
Wiring issue.

If you match any of these, check it over carefully. If you still can\'t find the problem, take it to a specialist.

OK. I've pretty much pinpointed it that its a wiring issue. I'm pretty sure it's inside the gearbox, so tomorrow after school I'll look at the screws and see if I have the right tool to take them out.

I thank you much for your speediness and knowledge, alexkmmll

Hold on a sec. Check over the external wiring carefully. I believe the only place that the wiring actually goes inside the gearbox is to go to the fire-selector and trigger. From what I've heard, this is most likely where your problem's coming from, but just to a double check to make sure, especially to anywhere where wires meet or connect to something.

External wiring looks ok...
some bends in some places, and some.... what looks like electrical tape in some places, though the gun came like that...

Anyway I do appreciate the help so, I'll stop for the night. I'll probably be on this forum tomorrow, for now I'm going to go take a shower.

Ok, sorry for double post.

Ok so, I patched up some places where the wire was bear and where there were cracks in the outer wiring. Nothing real serious though, so I still think its in the gearbox. However, I finally found out that the gearbox most likely has Torx Screws in it, but I have no Torx Screwdriver, which means I can\'t open it.

Been away for a bit, but here goes,

Your right !! the chances are good that the problem lays in the wiring harness, either inside or outside the GB, in SAFE mode the selector plate is so far removed from the switch assembly that a closed circuit is not possible.

When you get the shell open, check the opening where the motor passes the wiring on the way into the GB, most shorts start there, Changing motors, Pinion Gear replacement, bad motor height, strips away the insulation.

Check the contacts on the switch assembly, check the contact block make sure it´s not `Hanging ´ in the switch assembly.