End of story.

Because the Nexus 5X is a Google-partnered device, firmware is typically distributed in two formats: (for full system restoration via fastboot) and OTA Images (for manual updates without wiping data).

“Because sometimes,” he said, “the firmware is the only thing keeping a good phone from becoming e-waste. And because the H791 deserved better than LG’s silence.”

: You flashed a non-H791 firmware (e.g., H790) or corrupt EFS partition. Fix :

The H791 is also a Nexus 5X. Google provides official factory images for “bullhead.” Can you use those?

The most reliable source is the official Google Play Services Factory Images page (search for "bullhead").

First, Arjun installed — LG’s proprietary flashing tool, last updated in 2019. It refused to recognize the H791 in bootloop. Device manager showed “QHSUSB_BULK” — a Qualcomm emergency download mode.