Topic: 3DS Arm 11 error

My sons 3ds updated this morning and when restarted it came up with an exception error, Arm11 (core 1), undefined instruction.

Apparently it was previous hacked before we got it. I tried updating the boot file manually with the latest version but only resulted in the device not powering on at all.

I reverted back to the original version and got it back to the Arm11 error screen.

Any suggestions how to get it back to a working state? Complete format and remove whatever the previous owner did?

Thank you.

The 3DS is still a rather recent console, so as per the rules of the site, we can really give you any detailed help on how to fix a hacked console here.

I'm sure you will be able to find a solution by searching the error you're given.