Motor sound but no cycle.

[Bonesnap]

I recently bought a CYMA SVD and this is my first metal AEG.. I thought I knew every aspect of upgrading or repairing an AEG after years of Chairsofting :lol: . I tried to shim it and correct the AOE as alot of people recommend to do.
After all these little jobs, I close the gearbox, I try to shoot : nothing happens.
I thought I overshimmed, so I remove some on the top and I realize there a little sound coming from the motor but still, there's no cycle.
I tried with another stronger battery ( 8.4V => 9.6 Nimh ) and its the same little sound.
I tried to shoot full-auto with my unlocked switch but still the same.
I tried to reset the Anti-reversal latch and nothing changed.
I removed every shims and the gears are loose as hell but no change.
I raised and lowered the motor gear and they were a slight difference on the volume of the sound but there's still no cycle.
The gun is brand new, so there's no broken or worned pieces as I can see.
The gun is a copy of the Real Sword SVD with 4 gears.

For now I'm very frustrated with this, I can find the problem.. So what do you guys think?

[Spike]

This will sound weird, but switch the polarity of your motor wires and try it.

[R.I.T.Z]

does the nozzle move back and forth while the motor turns?

[DustMagnet]

Voting for piston rotated out of guide rails so sector gear cannot engage piston teeth.

(In that case you would still see the nozzle move back and forth.)

[Bonesnap]

I'm really stupid.. Thanks Spike, I can't believe it worked.. And thank you everyone for taking time for helping me, it was so simple. Everything is fine now.. I just switched the red and black wire from their socket and it shoots as it should.

Thanks alot!! ( I'm terribly sorry for this newbish error )

[ThunderCactus]

it happens
at least we don't flame people for it anymore lol

[lurkingknight]

it's pretty damn easy to flip the wires sometimes... the motor endbell is not always very well marked. There's red paint on the brush spring pin on the positive side on some... others have a tiny plus etched into the plastic. The paint can sometimes wear off over time so it might be a good idea to find some way to mark it so you can see it better.

[Ron-E]

Originally Posted by Bonesnap

I'm really stupid.. Thanks Spike, I can't believe it worked.. And thank you everyone for taking time for helping me, it was so simple. Everything is fine now.. I just switched the red and black wire from their socket and it shoots as it should.

Thanks alot!! ( I'm terribly sorry for this newbish error )

I'm sure this has happened to everyone at least once. I know I've mixed them up a few times specially using the SPECTRE mosfet, for some reason they decided to go the opposite from everyone else with their wiring

[Spike]

Don't quote me on this, but aren't 4 gear SVD gearboxes supposed to be wired backwards anyway?

[Bonesnap]

Originally Posted by lurkingknight

it's pretty damn easy to flip the wires sometimes... the motor endbell is not always very well marked. There's red paint on the brush spring pin on the positive side on some... others have a tiny plus etched into the plastic. The paint can sometimes wear off over time so it might be a good idea to find some way to mark it so you can see it better.

In my case, the motor has a clear red circle on the pin. And I really thought the wires were in their respective socket.

Originally Posted by Spike

Don't quote me on this, but aren't 4 gear SVD gearboxes supposed to be wired backwards anyway?

No, they're the same as the 3 gears, except the motor is in the grip. But the wiring system are close.