Several smartphone models introduced by LG Electronics between 2015 and 2016 were discovered by users to have manufacturing defects, all of which eventually cause the devices to become unstable, or suffer from a bootloop, rendering them effectively inoperable.
When officially acknowledging the bootloop issues with the G4, LG stated that it was caused by a "loose contact between components"; Android Authority explained that "a loose connection between power supply or memory components could certainly cause a phone to fail to boot up properly, due to a lack of system stability or not being able to access vital memory.
[1] In January 2016, LG officially acknowledged that some G4 models suffered from a manufacturing issue "resulting from a loose contact between components", that caused them to experience symptoms such as failure to reboot.
Andrew Williams in Trusted Reviews was more specific, saying that "the cause of the problem has been confirmed as a fault in the soldering of one of the connectors on the device's main board".
[3][4] In September 2016, reports began to circulate that similar failures were being encountered with the Nexus 5X manufactured for Google by LG, particularly whilst upgrading to Android 7.0 "Nougat".
In January 2018, due to stock shortages, Google's wireless network Project Fi began to offer the Moto X4 as an alternative replacement for bootloop affected Nexus 5X owners.