Lenovo laptops primarily beep in three situations,
- When typing too fast or pressing many keys at the same time
- When plugging in or unplugging the AC power cable
- During startup.
The first type of beep indicates an invalid key combination warning as the laptop tries to interpret the simultaneous keystrokes as a key combination. The second situation is also a simple alarm denoting the respective action and does not affect your system in any way.
You can disable both of these beeping features by changing your BIOS settings. You need to access the BIOS (F1 or F2 key) and go to the Configuration or Config tab to find such options.
Startup beeps, however, indicate POST errors and are more serious. The laptop runs a Power-On Self-Test (POST) sequence from its BIOS to check all hardware components before handling the control to the kernel of the Operating System. If it finds any issues during this diagnosis, your computer starts beeping in particular sequences depending on the exact issue.
Resolving POST Beeps
If the screen also displays some error message along with the beeps, you can try searching those on the internet to obtain relevant causes. If not, try listening to the beeps carefully and note down the sequence. Then, you can search for the exact cause corresponding to that sequence on the official sources.