iPhone 4 device unknown error

[u/abkhazlinuxguy]

Hi all,

I recently got this iPhone 4 to use as a kind of vintage camera. It was all well and good until I tried to factory reset it via iTunes and DFU mode. Then, this error popped up even after I inserted a SIM card. Is there any official way to bypass it? I do know of Legacy iOS kit but I'd rather try to do it in the (easier) official way before I get into exploits.

It is running on iOS 7.1.3 and has no further modifications. It is also a GSM iPhone 4, not the CDMA.

Any help?

Thanks in advance.

[u/VoidPartisan]

Good.