I must have done something wrong...

[Payback]

If you got the piston in wrong, it shouldn't have closed all that easy when you tried to bolt it back together.

My first gearbox took my 10 tries and till about 3am before i got it back together. Watch plenty of videos on how to do it, look at the details of how the anti reversal latch and trigger are configured. Make sure that all tabs/grooves line up on the piston, spring guide and other bits.

When it's back together you should be able to move the nozzle a bit, and the gears should be able to rotate with a screw driver to them to a point.

Again, watch more videos and you'll get it down. It's really hard to get an exact answer here since without hands on it's nearly impossible to diagnose your problem. Usually a good place for last ditch ideas and help on narrowing down the problem, or getting advise on grammar and making sure your motor is connected the right way

[Cloudyrains]

I really suggest looking up some videos of how to work on your gearbox or biting the bullet and taking it to Jesse at ASNW. He does an immaculate job with AEGS. While you're there, you might as well get a tightbore and a new bucking to help justify bringing it in.

[dod_rules]

I finally got it back together and firing perfectly! The second time I opened it up, I took everything out and put it back in from scratch, and I guess I did it right this time.
Now instead of working on a gearbox all day tomorrow, I get to go try out my new gun!

[phiz]

I finally got it back together and firing perfectly! The second time I opened it up, I took everything out and put it back in from scratch, and I guess I did it right this time.
Now instead of working on a gearbox all day tomorrow, I get to go try out my new gun!

Congrats, you are now an experienced AEG tech. Same way everyone else learned.

[Osprey]

Have you hook the battery to the motor directly with out gear's being in the way? Doing this can double check if the motor is lock. (if the motor runs fine it's fine) Also try to loosen your motor in the pistol grip that also might be the problem. Look for a assembly guide video of your gearbox type this can help you assemble the whole gearbox form the ground up. Other then that that's all I know about motor issues

[airsoft_hk]

Well, I just took the gearbox apart again, and it looks like I put the piston in wrong! I have yet to put it all back together, but hopefully I found the problem. I'll try again tomorrow.

Good Luck!