ISC SIG Gearbox issue
 

I hope the video does justice to your ability to diagnose the issue, but a friend of mine has had this gun for over a year and it was working just fine. Never opened the gearbox, and one day it stopped firing, has a higher pitch wine, no air puffs out, gears don't seem to be stripped (I opened it up). What's the problem?

Being to tired to open it up again, I'm thinking it might be stripped plastic teeth on the piston? I'm sure the gear timing is all kinda of messed up but I wasn't concerned about it when I put the gearbox back together, which is why I'm sure it's not firing the same every time I pull the trigger.

Thoughts???

Thanks in advance, been years since I worked on gearboxes.

https://youtu.be/f8rCGnfc23M

You probably stripped the piston, or broke the back off of it. Also, there is no gear timing in AEGs.

You opened it up but didn't even look at the piston?
...

Yup that sounds like a stripped piston.

I see your location is set as brantford, im in town if youd like someone to take a look?

I was suuuuuper tired when I took it apart last night, so I was expecting stripped gears and when I didn't find it I was just like "put this thing back together before you forget where you put the parts". I'm going to take it apart again and take a look and see what I find, just thought I would post and see what you guys thought so I didn't over look something again. Thanks for the offer to take a look at it though, I'll message you if I can't find the issue this time.

No problemo :) lets us know if you find anything