Before sliding the trigger button retainer back into the rails molded into the front cover, be sure that the cylindrical post attached to the #1 button is sitting flat on the green rubber electronic switch cover. Failure to do so may lead to problems with fit during reassembly, and may cause the controller to not recognize inputs from the #1 button during operation.

The trigger button assembly is properly installed when the lip on the trigger button retainer sits flat against the motherboard.