G&G G3 Optical ETU & MOSFET 16AWG Wire Set

"Drop in fit for the sgr 556, couple issues though.

While it is a drop in fit, its a pain to manage the wires and tuck them under the rear hold down block.

I was able to pair this to the remote just fine, but for some reason it was semi locked, and no matter what I did I couldn't get it to unlock full auto, maybe this is meant for their DMR which uses the same gearbox. I eventually just combined my old blown mosfet with this new one. This etu is made of 2 separate boards sandwiched together, and they pull apart fairly easily. The side the wires are soldered to, seems like the power handling side, and the other side that can be pulled completely off seems like the logic/ic side. I took my old half and added it onto the new half, and that brought full auto back.

I fried my original one while using an 11.1v 2200mAh 25c lipo, I had the lower half split apart and was just running the gears by themselves in full auto, and after about 5 seconds of free spinning the gears on auto and the fuse popped.

So it was either going to happen eventually on 11.1v anyways, or the gearbox doesnt like being run open, in that case it the etu should sense the gun is split and not allow something like that, especially considering the last round optical sensor is already on the upper half of the gearbox anyways.