Thanks for sharing. I had a power outage last night and my 2413U didn't recover automatically. Physically unplugging it and plugging back in resolved it, luckily.
I say luckily because has anyone else looked at the CrAzY eBay prices on used Insteon PowerLinc 2413U USB Power Line Modem PLM lately?
~$400 It might be too late for many of us to add spares.
As alternative option to trying to DIY it. There has been a listing on eBay for years, someone fixes them for $55 when they stop powering on. I do expect him to raise his prices given the current market.
https://www.ebay.com/itm/284787251657?hash=item424ea499c9:g:j90AAOSwk0ViXuuG#vi-desc-maincntr