my 4x4 is not working and my braking systm is also not engaging ( do not here it ) checked the fues and also tried another switch also tried friend 4x4 control box under the seat worked on his but my 4x4 still out

 

Is anything flashing on the dash meter screen of your quad when engine is running?

 

no

 

If nothing is flashing on the meter, then the problem may reside in the igniter or connection/wiring to the igniter. Try your friend's igniter if it is the same model.

 

my bros 4x4 on his brute wasn't working not to long ago.. but it turned out to be that he broke the shaft the spins the front wheels

 

I think the original poster's problem is electrical related, not mechanical, because he states 2 problems:
1). No 4x4 engagement
2). No engine braking
Rarely 2 mechanical things go bad at the same time, but if one electronic control unit goes bad, multiple things may not work properly.

You said your friend's control unit did not work on your quad. What if you try your control unit on your friend's quad, does your friend's quad work properly? See if the problem follows your control unit or not.