DSU Loader is an Android feature allowing users to download and boot a “Dynamic System Update” image. Given the complexity of the feature, it is placed inside developer options. Still, many innocent users discovered the feature and experimented with it. Unfortunately, that leads the phones to a bricked state (stuck in fastboot mode) and with no means of recovery.
The DSU Loader feature gives an error and fails to work on most Nokia phones. But in case it works, the phone is rendered useless. DSU Loader downloads and uses GSI (Generic System Image), signed and published by Google. This custom image fails to boot on a Nokia phone because the bootloader is locked (Only OEM-signed images can be booted on a locked bootloader). Eventually, the phone remains stuck in fastboot mode because it has no bootable OS available.
I first noticed this problem on a Nokia X20 and Nokia X10. The DSU Loader gave an error on my Nokia XR20 and didn’t download the GSI. Recently, I have seen many Nokia G50, Nokia G60, and Nokia X30 (TA-1450) users bricking their phones after using a GSI image from DSU Loader. It is okay if your device is under warranty, as Nokia will repair it for free. But if you have imported the phone from another country, then even Nokia Care will deny assisting you in fixing your smartphone.
I have also seen numerous reports from the owners of OnePlus phones. The phone manufacturer should not include a feature that can render the phone useless. It should be disabled unless the user unlocks the bootloader.
Do not use DSU Loader on a locked bootloader!
If you stumble across this post before using the DSU Loader feature, please be warned. If your phone’s bootloader is locked, do not use the DSU Loader feature to install a DSU GSI image (Android 14, etc.). Nokia does not allow bootloader unlocking. Only some phones can be unlocked using unofficial workarounds. Nokia also does not publish any signed GSI images that can be used for testing and experiencing other versions of Android.
Similarly, if you have a phone from another brand (except Pixel), please do not use the DSU Loader unless your phone’s manufacturer has official instructions about using it – in which case they’d be publishing images signed by them for the DSU Loader.
How to fix a phone stuck in fastboot mode after using DSU Loader?
So, your phone is already bricked? And you’re trying to find the means of recovering it? The best way to recover a phone bricked by DSU Loader is to flash the official firmware. The firmware will overwrite the DSU GSI image with the official OEM-signed image, which should boot normally.
For Nokia phones: Nokia phones follow a strict anti-rollback protection feature. So, you must flash official firmware with Android OS and SP levels being newer or equal to that in the GSI image. There are very few options to flash firmware to a Nokia phone. You can use our Nokia flashing service, which is available for most Nokia phones. I have fixed 2 Nokia X30 5G (TA-1450) devices bricked for using DSU Loader. You can join our Telegram group to discuss the problem and find potential fixes.
For other brand phones: Check your manufacturer’s website for instructions about re-installing the stock ROM. It can work on some phones without needing an unlocked bootloader. You will likely need to visit the care center of the brand or use their online pick-and-drop repair facility. If it does not exist, you should look for remote services from various providers, usually available for Xiaomi, OnePlus, Oppo, Vivo, OnePlus, and Realme phones.