4XX, 4XXX, Dirt Dog - Brush motor
The brush motor in the models listed above is controlled by a 6 pin SMD on the main printed circuit board. This device can fail in one of two ways. 1) Always open - Which causes the brush motor to never spin or 2) Always closed - which causes the brush motor to always spin and never turn off until the battery is removed. Presented here is a solution to both of these brush motor faults. It involves dis-assembly of your Roomba, removal of the internal circuit board, removal of the existing failed component, and the installation of a much better, and bigger TO-220 N-CHANNEL MOSFET.
You can order one of these MOSFETs for your Roomba for $5 plus $1.75 USPS shipping by clicking the "Buy Now" button below. Select either US $1.75 or International $3.00 shipping in the drop down box.