apple tv
apple tv stopped working after changing resolution
Question marked as
Setting a new screen setting would need confirmation – without that it should jump back to the previous setting.
When e.g. connecting to a different TV, the previous video setting may not be valid anymore. Then you can cycle a set of resolutions and video settings until you find a valid and visible one, then fine-tune from there. See the 2nd bullet point on: If your Apple TV doesn't turn on - Apple Support