A few month ago, I wrote about my wireless mouse at home suddenly stopped working (losing sync to the receiver) and how to fix it.
Now it happens that I got an eVolution Orca (the successor of the Marlin) at the office. Guess what happened... A few days ago, the keyboard stopped working... The Orca doesn't have any LEDs or switches and changing betteries didn't help, so I called the support hotline again. Indeed there again is a method to reset and re-sync the keyboard: Take out the batteries and leave them out for 5 to 10 minutes. Indeed that worked for me.
I wonder what's up with the Cherry eVolution devices that they occassionally lose their connection. With my Marlin wireless desktop at home, the mouse stops working every few weeks and has to be re-synced like described in my other posting. And now it's the eVolution Orca at my office too. That doesn't happen more often hopefully, since re-syncing means to take out the batteries for 10 minutes, which would be really annoying in the long run.