Qualcomm Usb Composite Device 901d -

If you are certain your device is functional (a working phone in recovery mode, or a development board), follow these steps to install the correct driver.

A: No. ADB uses a different PID (usually 18D1 for fastboot or 0BB4 for HTC). 901D is strictly for serial diagnostics and Firehose SBL communication. qualcomm usb composite device 901d

This is the most critical section for smartphone users. A persistent that appears even with no USB cable connected or immediately upon powering on the phone indicates a hardware-level short. If you are certain your device is functional