Thanks for the post Drew,

Most likely you have a loose wire connection, as this is the most obvious reason for the symptom it's experiencing.

I've attached a .pdf parts breakdown of this drill/driver for your reference:

documents.milwaukeetool.com/54-06-2611.pdf

- I would take a look at all wire leads and confirm none are burnt. Check all wire connections from the Brush Card to the Switch, Terminal Block & Motor (if applicable).

- Check the leads that connect to the Brush Card to confirm they're snug & not loose.

- Check the #12 Terminal Block (on the parts breakdown) to confirm the terminals are in good shape, and that the switch is snug.

- Check the Springs that hold down the carbon Brushes to the commutator on the motor armature; confirm Brushes aren't worn down and that the springs are putting tension on the Brushes.

Hope this helps, reply with any additional questions you may have and I'll do what I can to help.

- MTR