the particular component came out of a dewalt dw 983 xrp cordless drill trigger. the component was literally split in two and i no longer get a variable speed when i pull the trigger. its an old 14.4v drill. i made a lithium ion battery back for it in a 4s configuration with a 40amp battery management system. the batteries used were samsung Samsung 35T 21700 Battery Grade A Lithium-ion (INR21700-35T). they are 35 amp max discharge batteries. i was just using the drill normally and i heard a pop. upon inspecting the battery and the battery management system board i saw that one of the transistors in the mos tube had fried and when i put the nicad battery pack back in to test and see if the drill was still working the variable speed was gone. it was just on at full speed or off. although i did hear a slight electrical whine up until the full speed kicked in. i think i need to wire an capacitor somewhere in the circuit to stop that from having happened but o well my mistake. anyways that is the whole situation and im thinking that i lost the variable speed because of the the broken component in the trigger. i will post some pictures of it. if anyone can identify what it is i would greatly appreciate it.