@bobo006, Ben, If you have already replaced the side brush motor and still not working, check the wires and connector for being, loose/damaged/corroded/check the connector with DVOM to ensure power is getting to the motor and make necessary repairs if defect found. If motor has not been replaced perhaps consider replacing motor. 1st link below is a guide to replacing side brush motor and 2nd link will get you inside to inspect the mother board for loose/damaged/burnt components. Good luck. I hope this helped you out, if so let me know by pressing the helpful button.
iRobot Roomba 655 Pet Series Side Brush Motor Replacement
iRobot Roomba 655 Pet Series Motherboard Replacement
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Did you solved the problem? I have the exact same thing, replaced the module, still not spinning :-(
crwdns2934271:0crwdnd2934271:0 Gerry Lambrechts crwdne2934271:0