Hey Jack, we currently have 3 Zebra s600's, 2 in use and 1 spare. I've recently added some zp550 printers on the 2 computers that have the s600's and screwed up the drivers for the s600s. I found software and got the s600's running again but seemed to cause a new issue. Basically 2 of the 3 are now periodically (1 always) turning on, running a diagnostic and then going to a state of "needs ribbon or labels" by showing Pause + Cancel + Ribbon/Label lights. They are older machines so it could be sensors failing or dirty but seems suspicious that this would start on all 3 at the same time. 1 printer seems to be working fine, 1 this is happening every few days (for a week) and the other seems to always start in this mode. I've tried turning off with Pause and Feed, then hitting mode 4 times and this helps sometimes but not always. Any thoughts, have you dealt with this before? Thanks Chris