Electrical

Broken.

To add just a hint of detail to that long-winded answer, there are two power circuits feeding it. If the radio has a clock in it and it goes back to 10:00 or 12:00 each time you start the engine, the constant memory circuit has the problem. That could be in the car's wiring but is more likely to be in the radio itself.

If the display goes out and the sound quits, same thing. Could be in the radio, (most likely), or the car's wiring.

Most likely your radio uses a separate amplifier mounted in the trunk or perhaps under a rear seat. If there is a problem with the power wire feeding that amp, you will only lose sound. Everything related to the radio's display and functions will work properly.