[kevincox]

Can't they have a signed "self-test" image that they can boot up and it checks the phone? This wouldn't have access to any user data but can boot up and check that all of the components are working. This sounds much quicker and more effective than prodding at the user's OS anyways.

[TheSoftwareGuy]

That sounds like repair mode

[GuB-42]

At least on my phone (Samsung), the "self-test" app is on the /system partition, which is where the user OS is, and you need to boot normally to use it. You can run it by entering *#0*# in the dialer, no need to flash anything.

Having a dedicated test image (like /recovery) is a possibility, but it wouldn't be the same environment as the user. The kernel may be different, maybe some runtime calibration data would be missing, and most customers want to see their phone working after a repair.

[recycledmatt]

In high volume test and repair environments this exists, but part of how they can do it is they erase and overwrite the data on the phone. When you don’t care about the users data this becomes much easier. Data migration is a pain. (Esp when it’s not yours)

[lghh]

I worked at a phone repair place for a few years about a decade ago. This would have been great! However, it wasn't something that existed.