The Madbull RAS Fix V2 is a small rail attachment to bridge the top rail of the upper receiver and the top rail of the rail system. Especially handy to keep free float RIS properly aligned and to raise optics for people who play with full face masks.
If you’re gun is not firing, not making any noise at all then its most likely a connection break. If the fuse is good then the next easiest place to check is motor connections. This video describes how to check the motor connections on an M4. The concept is the same for other model guns but the process may be a bit different.
The JG BAR 10 requires a bit of assembly. There is a manual with instructions but they can be hard to follow. This should cover it…