I have had my Slingobx for a year, and it worked fine. The cable guy came to fix something, and one of the little"eyes", (the sensors for the remote I guess), came off, I thought Iput it back wjhere it was. But wherever I move it, I cannot no longer change channels remotely. The volume works on the remote on the screen, but it will not let me change channels. I do not know what to do about this. Picture is fine, just can no longer change the channels.
If the lens came out of the emitter, and nothing else changed (including your cable box) it's likely broken.
Try the test in this article:
Advanced IR Blaster or Onscreen Remote Control Troubleshooting
If it does not work, you'll probably have to buy a new emitter.
Sorry about that...