[Solved]Trigger lockup by switching from full auto to semi
 

I finally had time to take the gearbox apart from this KA m4 that I bought from someone who said it has semi problem and his brother opened it..Okay, not a big deal..(original problem was that it skips one trigger pull, so no shoot, shoot, no shoot, shoot) I can hear that the gears seems to be over spinning or something..

After I open the gearbox, I immediately noticed the the anti-reversal latch's spring is installed backwards. Also the spring seems shorter than normal (usually the spring arm on the object itself wraps to the top of the anti-reversal latch, this one doesn't)

After I did that, I also checked trigger contacts, cut off lever and general wear & tear on the internals..surprisingly, nothing seems worn..So I was like great, put it back together.

now semi shoots fine now..HOWEVER, every time I switch to full auto, shoot a few rounds and then go back to semi, semi would lockup. To clear the lock up, I need to switch to full auto again, shoot a few rounds, and then semi would start to work. The semi shot after the clear seems to be weaker tho...

Im not sure what's wrong at this point..

Take a video, it cold be that your anti reversal latch is still not catching consistently.

will do that today

i don't think it's the same thing...mine is that only when I switch to full auto and shoot then switch to semi, semi wouldn't work. (sometimes it does, it's like luck)

if I only use semi there is no problem at all, it fires fine.


EDIT: WEIRD...got home and tested it again, now it's fine...I will keep on trying to see if it happens again...

Yes that's semi-lock, which was linked, which is a standard problem on AEG's if it's caught at a certain place mid-cycle. Since auto doesn't stop at the end of a cycle, it stops whenever you let go of the trigger.

I guess that's right...Didn't change battery or do anything it just stopped doing it...the day I posted this it was happening 90% of the time..

Couldn't get it to do this anymore which is good..
maybe it's because the day I tested was because the deans was freshly soldered on? the next day it's flawless...

too bad I can't fit a bigger battery in my peq box...only a 7.4v 1500mah 20c lipo..

Most likely the voltage on the battery dropped slightly because you were using it. Dropped just low enough that your gun stopped cycling into the wrong spot.
Try charging the battery again and see if it happens again.

As far as I know, the connection between a wire and a deans connector doesn't "age" and increase resistance. 110% certain it doesn't do that over the course of 24 hours lol