Check the battery polarity. Match the "+" and "-" polarity symbols on the battery to the markings inside the battery compartment
My headphones will not turn on.
- QuietComfort® 15 Acoustic Noise Cancelling® headphones
- QuietComfort® 2 Acoustic Noise Cancelling® headphones
Verify that the battery compartment is free of debris. Use compressed air to blow any dust or debris out of the battery compartment. Use rubbing alcohol and cotton swabs to clean the contacts within the battery compartment
Try installing a new battery