When using a ThinkPad T14, you may encounter a situation where a warning chime like “tiriririi” sounds and the system fails to boot with a black screen while a USB-C display is connected and the battery is almost empty. This article explains why this happens and how to fix it.
Conclusion
This is not a hardware failure. It is a side effect of USB-C specifications combined with ThinkPad’s power protection behavior under extremely low battery conditions. In most cases, reconnecting a proper charger and performing a forced restart will resolve the issue.
What is happening
USB-C handles video, data, and power delivery through a single connector. Even displays that do not provide power still participate in Power Delivery negotiation during connection.
When the battery is nearly depleted and a USB-C display is connected, the ThinkPad T14 may briefly detect a possible external power source. However, because there is not enough actual power to start the system, it triggers a protection mechanism, plays a warning chime, and stops booting.
Typical behavior
- Battery almost empty
- USB-C display connected (no power delivery)
- Warning chime during power-on or wake-up
- No Lenovo logo, black screen
- System boots normally after reconnecting a charger
This pattern is relatively common on ThinkPad T14 models.
How to recover
- Hold the power button for more than 10 seconds to force shutdown
- Connect an official or 65W+ USB-C charger
- Leave it charging for 10–20 minutes
- Press the power button once to boot
If needed, press the Emergency Reset Hole on the bottom cover with a paper clip for 10 seconds.
How to prevent it
- Avoid connecting a USB-C display alone when the battery is below 10–20%
- Always connect the charger together with the display
- Use a monitor that supports 65W or higher power delivery for long sessions
Summary
This issue is caused by the interaction between USB-C negotiation and ThinkPad’s power protection design. It does not indicate hardware damage or data loss. Understanding the mechanism helps you handle it calmly when it happens again.
