Revert to stock: how?

Roel20

New member
Jul 27, 2015
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Hey guys,

I want to sell my old backup phone Galaxy A320FL. In the distant past I once installed LineageOS 16, but now I'd like to revert completely to the original stock ROM.
So my question is:

Can one of you provide me with the steps needed to take to make this happen?
And preferably a link to the (Dutch / PHN) stock rom files wich doesn't limit speed to 100b/s
Also, when I boot the phone it always says KERNEL IS NOT SEANDROID ENFORCING and sometimes it gets stuck in boot. And when i go into download mode i get this:

It says WARRANTY VOID
Is that going to be a problem?

And I don't know if this matters, but I'm using Ubuntu.
So i have to use adb or something?

These are a lot of questions, but I hope you can help me a bit on this.

Roel20