I have the no-battery refill carts. I have not hit a refill point. I have removed all cartridges with power on. disconnected from wall for 15min. Turned back on and re-insterted all carts. LK says "not recognized". When I install them individually and close lid to check each one installed, LK appears to be working until all cartridges are reinstall. Then it goes back to "not recognized" status.