Oral B IO Toothbrush - Bootup Error and Possible Fix - Disassembly and Reassembly

Oral B IO 9 disassembly and reassembly following error where toothbrush would not turn on or boot past "Hello." It would not charge or boot and would also frequently shut off suddenly. The brush was disassembled and dried and would intermittently work. The video describes what has led to my brush being revived, but it has not yet been long term at the time of upload. I suspect this is the result of moisture intrusion. I would recommend just air drying. I am not sure how the WD40 may interact with plastics/the board over time. A contact cleaner may be more appropriate, but isopropyl alcohol may be a safer solution if air drying does not work.