half the drone doesn't work

[Richard Lang]

Hi I'm new to this hope someone can help.
I've got m:tech sky drone pro V2 and at first time using it I crashed twice then got the hang of it.
The next time I used it I've started having problems the return button does nothing I'm sure.
Now half the drone doesn't work at times, (blades don't turn or looks like its sticking).
When I pick it up the had it on it side the other blades stop working then the others start working.
It looks like it can't make it mind up witch blades to turn.
can anyone help me I've cleaned it checked the gears still the same problem.

 

[Jackson]

Does the manual show a calibration procedure? It will involve some sort of sticks movements.