Adding used RBS50 to my existing network

Looking for ideas on how to add a used (purchased off Ebay) RBS50 to my existing network. I have tried to reset using the pin hole but no luck getting the amber light. I have "factory reset" the unit with a 30-30-30 reset. I have gone through both the app addition/sync as well as the manual addition/sync. Several attempts showed the blue "strong signal and syncing light", only to change to magenta at the end of the cycle. I've tried just plugging in the RBS50 and letting it set for an extended time (this last one was over 12 hours), but it still just shows the magenta light. I have tried syncing the newly purchased (used) RBS50 to my existing RBS50v2, again all I got was the magenta light. After a lot of reading on this forum (Thanks to all contributors!) I'm wondering if I need to manually update the firmware on the used RBS50 I purchased. When I say manual I mean a hardwire between the RBS50 and a computer to upload the most recent firmware. My existing network (RBR50 and RBS50v2) work just fine. Trying to find a way to add a used (new to me) RBS50. Help!