A field technician is deploying mobile workstation laptops for a group of engineers who require dual external 4K video output. The technician connects a multi-port docking station to the laptop's built-in USB Type-C port, but neither external monitor receives a video signal, even though USB peripherals connected to the dock function normally. The technician assumed that the physical USB Type-C port would support DisplayPort Alternate Mode and Thunderbolt high-speed video transmission. Which of the following best explains the root cause of this issue?
- AThe internal OLED display backlight inverter board has experienced a power fault, disabling video transmission across all external expansion ports.
- The physical USB Type-C port is connected to a host controller that only supports USB data protocols rather than DisplayPort Alt Mode or Thunderbolt standards.Answer
- CThe laptop's smart card IMSI hardware identifier must be updated in the system BIOS to grant display output permissions over USB interfaces.
- DThe laptop battery requires a full deep-discharge calibration cycle to trigger high-voltage power delivery to the external display controller.
Answer
The physical USB Type-C port is connected to a host controller that only supports USB data protocols rather than DisplayPort Alt Mode or Thunderbolt standards.
Physical USB Type-C connectors can carry multiple independent protocols, but transmitting video requires hardware support for DisplayPort Alternate Mode or Thunderbolt. When a device's host controller only implements standard USB data protocols, USB peripherals plugged into a dock will function normally while external display signals fail to output.
Step-by-Step Solution
Key Concept
Distinguishing physical mobile connector form factors from supported protocol standards (USB-C vs. DisplayPort Alt Mode / Thunderbolt)