Hi, thank you for contacting JustAnswer.com. My name is Russell. I will do my best to provide the right answer to your question.
I think that what you are asking about is cause for serious concern.
There are some things to check for that could cause, or contribute, to the problem.
1. Is the Yamaha DJX plugged into the wall outlet ? or is it powered through a surge protector?
2. Was there an electrical storm, thunderstorm, or similar weather, and/or a power failure, in the region prior to the problem first showing up?
3. Does the AC adapter cord look un-stressed and not severely bent at any point?
4. Are all cords firmly plugged in ? in the AC adapter.
5. How old is the DJX in question?
There are things that can be tried, but ultimately it may be a matter so severe as to require that the Yamaha DJX be service-repaired, unfortunately. This is quite likely to be what is required to get the device working again.
If so, what is your local zip code, please? so that I can look up listings for nearby Yamaha Authorized service co.s that can repair your DJX.
Please let me know, by Reply To Expert, and I will assist and advise you further.