View source for EliteBook 850 G5 Not charging with broken USB-C port

{{Repair Guide
|Device=EliteBook 850 G5
|Affects parts=USB C port
|Needs equipment=CH341A, screwdriver, possible solder
|Type=Teardown, Software
|Difficulty=2. Medium
}}
{{stub}}

== Problem description ==

*After disconnecting a USB-C charger, laptop reports power is still plugged in and charging indicator remains solid amber
* Any USB C peripherals are not recognized

== Possible permanent fix (just theory for now) ==
This laptop was built around the same time as [[Thinkpad T480]] and USB-C charging was new. The T480 had issues with the thunderbolt port due to the firmware constantly writing to a 1 MB eeprom chip. Eventually, the chip's storage would overfill and corrupt the firmware. 

On the back of the 850's motherboard, there is a winbond 25q80 chip<ref>https://www.badcaps.net/forum/troubleshooting-hardware-devices-and-electronics-theory/troubleshooting-laptops-tablets-and-mobile-devices/bios-requests-only/79339-hp-elitebook-850-g5-bios-password</ref> that is 1 MB. Another user posted the dump of the chip that contained no null padding and seemed like the firmware was written twice and did not have enough room to write a third time. 

[https://files.catbox.moe/ho7chu.bin Dump of Elitebook 850 G5 25q80 chip] 

[https://files.catbox.moe/3bresl.bin Dump of original T480 eeprom (notice size is smaller than 1MB and does not have padding)]

[https://files.catbox.moe/cz7za8.bin Dump of correctly padded T480 eeprom]

Checking the official driver page and extracting the thunderbolt firmware for this Elitebook, the .bin file is 245 kB which is similar size to the original T480 firmware.

In theory it might be possible to create a padded version of the Elitebook's thunderbolt firmware and follow [https://github.com/SkippyHub/Lenovo-thinkpad-T490-thunderbolt-eeprom-fix these steps].

== Temporary Solutions ==
I bought a USB C to barrel jack connector very cheap on AliExpress which bypasses the faulty USB-C for charging.

Otherwise, doing a hard reset (press the power button for 10 seconds and the caps lock and num lock will flash) returns USB C functionality.