Skip, he did not ask for new chrono recommendations but I guess you get a free pass when you are an evil minion dressed like agent 47.

My general advice for electronic devices is to first take out battery and wait/press random buttons/reset device and if still not working open up to inspect for obvious loose connections and burnt components and determine if i'm able to resolve the issue easily. If not I leave it be or if device is expensive I take it to expert as repair is super cheap in my country.
 
Reavers suggestions are a good place to start. I have a chrony that would flash err1-err9 due to poor lighting conditions. Are you using it outdoors only or indoors? Try placing it directly under an overhead light(must be incandescant and NOT fluorescent) and try powering it on to see if the error goes away.
​Do you use sunscreens and if so is the plastic still white or have they changed to an aged yellow color? If they have aged to a yellowish color then perhaps they are not letting enough light through.

If you havent already perhaps an email to the manufacturer would be a good idea.