I have been testing an application that uses ZQ520 devices for printing. While testing some code that stores images onto the printer, I accidentally had it running the LinkOS iOS SDK's "storeImage" command over and over again in a loop, each time saving the same image in the same location. Now the printer keeps flashing both the "no media" and "processing data" icons, even when there is definitely valid media installed. I tried power cycling the printer (even removing the battery), and this doesn't fix the issue. When it powers back on, the "no media" icon keeps flashing (despite replacing the paper with a new roll) and when I try sending ZPL for it to print, it usually prints just about an inch of the job, then stops (with the "processing data" icon now forever blinking). I found that if I keep pressing the "feed" button, eventually parts of the queued up print job(s) start printing, erratically.
Do you know what explains this issue? It is alarming that the printer seems to be unusable now. I'm considering trying to reset it to factory settings, but I first want to know how it got in this situation. I didn't think I was doing anything particularly out of the ordinary - should I be more cautious about storing images onto the printer (or overwriting them)?
Also, do you have any troubleshooting suggestions for getting the printer out of this state?