CTL TECHNICAL BULLETIN 010923
Full technical brief - LINK
RE: NL7 series (LI9) Battery Replacement Guidance
**NOTE** This is only needed when batteries fail in the field
CTL analyzes and monitors repair trends over model life. If there are trends, an investigation is opened with the ODM (Original Device Manufacturers), and Google. In some cases, CTL, the OEM, will open a support bug with Google. CTL’s goal is to communicate and be transparent with customers as issues are found and to solve these issues as quickly as possible.
The original and only shipping battery in the NL7 series labeled SQU-1709 is no longer available. The SQU-1901 battery is the replacement battery and is also in short supply due to supply chain constraints.
If a device that has an SQU-1709 battery requires a battery replacement and a SQU-1901 is used the RO (Read Only) firmware will need to be updated to allow the Chromebook to function properly. If the Chromebook is not updated it may fall into battery lock mode when the ESC-REFRESH-POWER keys (Recovery Mode) or when a REFRESH-POWER (hard EC reset) is initiated. This would require plug-in power for the Chromebook to recover.
A failed battery can be detected by not powering on and or by holding down ESC RFR POWER and getting the chrome OS missing error. This may require a battery replacement.
If you replace a battery SQU-1709 with a battery SQU-1901 the Chromebook will not enter recovery mode and will not power on without power assistance. The Chromebook could also battery lock when not used for many hours. This requires a power “bump” to turn on the Chromebook.
In order to regain full function, the following steps are required for correct battery function:
- Deprovision and place Chromebook in Developer mode (ensure the device is not in an auto-enroll OU)
- Remove the bottom / D cover. (If the existing battery is not working at all, the SQU-1901 will be able to get through these steps to flash if needed)
- Plug in the Chromebook
- Press ESC + F3 (refresh) + Power
- Press CTRL + D and then ENTER to turn off OS Verification (If not turned off the shim image will not be recognized)
- Immediately power down the Chromebook once OS verification is turned off (Do not transition to Developer Mode)
- Disconnect Power
- Remove the old battery SQU-1709
- Install the new battery SQU-1901 - DO NOT plug into the Mainboard yet
- Insert the USB SHIM
- Press and hold ESC + POWER and then Plug in the Chromebook
- With a USB drive run the Short Shim to program the firmware
- The Chromebook automatically reboots into the factory test user interface information has been copied
- Power off the notebook and disconnect the power cord
- Connect the battery to the mainboard
- Connect the power cord
- Power on and start the SHIM testing process with the space bar
- Finalize the SHIM process
- Install the bottom / D cover and all the screws
- Plug into power up and verify the charge
- Unplug and test the battery function and update OS as needed
If you have any questions, please submit a ticket for CTL to service the device if covered under warranty.
Please contact us if you have any questions.
Jeremy Burnett - firstname.lastname@example.org or 971-327-0074
CTL support team