What's the reason for the navigation screen being black but the buttons making sounds?

[SanXavier]

If the screen is black but the sound is normal, try switching to a familiar interface and tap the touchscreen to see if it responds. If the touch function works normally, then the issue may lie with the display screen. More details are as follows: 1. Potential issues with the display screen include: LCD screen damage, abnormal LCD backlight driver, malfunction in the signal circuit, display decoding issues, or problems with the core module. 2. If the touchscreen is not functioning properly, the first suspicion should be a damaged touchscreen, which can be replaced. 3. Then, check the touch circuit. If the wiring is confirmed to be intact, the issue may be with the decoding chip or core module not working or being damaged.