Fixing an iRobot Roomba 530 with Error 9. This repair also resolves the "circle dance" issue and works for 500, 600, and 700 series robots. My Roomba wouldn't move forward, only backwards and in circles, even after a thorough cleaning. That's a sign of bad IR LEDs and/or phototransistors. See the links below for the parts and tools I used:
IR LED & Phototransistor Pack:
https://www.ebay.com/itm/115272998007
Soldering Iron:
https://amzn.to/2URUMJe (affiliate*)
Solder:
https://amzn.to/3bKn5jl (affiliate*)
Desoldering Wick:
https://amzn.to/39yiwHA (affiliate*)
Helping Hands with Magnifying Glass:
https://amzn.to/39upUDL (affiliate*)
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