JG M4A1 not firing?

[Lawless]

did a brief browse and search couldn't find exactly what I'm looking for, apologize if I missed a similar thread...

anyways, just got a JG M4A1 couple of months ago. barely used it, less than 200 rounds through it. was firing and all of a sudden it stopped. figured it was battery dead, charged it up fully, tried again, nothing.

at first I could hear something trying to move when pulling the trigger but it stopped. taking apart the receivers I could see the piston seems to be stuck back, and from pictures I've seen of others' gearboxes, it should be forward.

never cracked one open before so don't wanna mess around, but can anyone help, please?

[Crunchmeister]

First, make sure your fuse is intact. Sounds like the gun initially locked up but was trying to turn over when you pulled the trigger. Chances are that stopped because you blew your fuse.

The first thing I'd try (once the fuse is replaced) is to lower the motor height a bit to see if that helps. You do that be looseing the allen srew in the middle of the grip plate on the pistol grip. Just loosen a bit at a time and see is that helps.

If that's not it, then it could either be shimmed too tightly or there's something broken inside jamming up the action.

[Styrak]

I'd assume it's a blown fuse. Check that first.

[kalnaren]

Originally Posted by Lawless

at first I could hear something trying to move when pulling the trigger but it stopped.

Rule #1: If you pull the trigger and it doesn't turn over, DON'T KEEP PULLING.

It sounds like your box locked up, which happens sometimes and all that is needed to fix is to trip the anti-reversal latch. But because you kept pulling, like Crunch said, you probably blew the fuse.

[Lawless]

damn, even if it was just like two quick pulls? what/where is the anti-reversal latch?

will update when fuse has been checked.

[Shirley]

Anti reversal latch, if not, try motor adjustment. Does it click click? Don't keep pulling the trigger, you'll burn out your motor and/or battery.

[kalnaren]

Originally Posted by Lawless

damn, even if it was just like two quick pulls? what/where is the anti-reversal latch?

Inside the mechbox, near the botton. It locks into the bevel gear to prevent the mechbox from reversing when partially wound.

[Thenooblord]

i had this happen to a gun that i had to fix, and its not what any of you guys have said
when it happened to me, what it was is the screw holding the piston head had come off and jammed the piston before it could get all the way back, making it impossible to fully cycle and return forward,
if you want i can take a look at it

[kalnaren]

Originally Posted by Thenooblord

i had this happen to a gun that i had to fix, and its not what any of you guys have said

Oh really? And how many mechboxes have you worked on? How many times have you had them jam? I've jammed my G36 mechbox many times... three times alone last time I was working on it. The problem every time was that the battery was too low to fully crank the box, resulting in a partial winding that jammed it. The solution was tripping the AV latch.

I'm not saying what you had happen couldn't happen.. but that's the first case I've heard about it, and myself, and everyone I know, has had a mechbox jam because of the reasons stated by everyone else in this thread.

[Thenooblord]

i wasnt implying that you were wrong, i was just saying that it happened to me and it was another possibility, and what he described is exactly what it was like when this happened

[Lawless]

yep, it's a burnt fuse.

the markings weren't engraved very well so I can't make out what it says. would anyone know what fuse to get?

[kalnaren]

Originally Posted by Lawless

yep, it's a burnt fuse.

the markings weren't engraved very well so I can't make out what it says. would anyone know what fuse to get?

15A or 20A. Truth be told, you'd probably be ok with a 25A one.

[Styrak]

Originally Posted by kalnaren

15A or 20A. Truth be told, you'd probably be ok with a 25A one.

Or soldering the fuse contact wires together.
A lot of people run guns without fuses.

[kalnaren]

Originally Posted by Styrak

Or soldering the fuse contact wires together.
A lot of people run guns without fuses.

I know, including myself. However, a properly installed fuse will not have a negative impact on the performance of the gun.

I found in mine the problem with the fuse lead was the current loss over the additional connectors. In the case of the OP, since he managed to blow the fuse once, it was probably a good thing he had it in there. Otherwise he might have damaged something.

[Lawless]

does it matter if it's an "automotive type replacement" or microwave one? those seem to be the only 15-25A ones.
http://www.thesource.ca/estore/Produ...roduct=2701268