The best way we know to attach the plug into the USB adapter is to go in at an angle. The plastic on the plug should have a more rounded side; we would suggest putting that side in first and then push down the other end (you may need to pull the tab out to make it easier to insert). One thing to look out for is the metal prongs on the body- when inserting the rounded end of the head, make sure the top prong is being inserted into the slot of the head; usually, if the first prong goes into the slot, the other prong should go into the other slot with no problems.

Be sure to refer the attached graphic.