How does Apple prevent people from unlocking their brand new iPhone 3GS 8GB? They replaced one of the components inside!
As it turns out any 3GS produced after week 28 of year 2011 (sometime in July) is made with
Toshiba baseband Numonxy 36MY1EH or 36MY1EF chip, as opposed to Infineon baseband 36MY1EE NOR chip.
If you attempt to flash it using iPad baseband 6.15.00 there is a risk of bricking your phone! Take this as a warning!
The typical symptoms of a corrupted baseband NOR chip are:
- No WiFi
- No ECID
- No IMEI
- No Bluetooth
- Restarts itself every few minutes or so
Please take note of serial number of up to XXX109XXX may or may NOT be compatible with the iPad baseband. See example below:
XX109XX = 1 is the year of 2011 and 09 is week 9 of 1 year
If the serial number is XX931XXX that means it was produced in 2009 in week 31. Thus, it’s safe to flash it with the iPad baseband. If you’re already encountered with the errors above, consider having your logic board fixed. See here.
You can use this website to check your iPhone’s production year and week based on its serial number. You can also physically check if you have an older chip (some refurbished units are using older chips).
If you intend to unlock your iPhone by flashing it with an iPad baseband, please check your serial number first! If yours is made after week 28+ of 2011, then consider downgrading to 5.13.04. Learn more about it here.
AT&T iPhone 3GS owners with either new or old chip can use this to permanently unlock it.
So which year production and week number is your iPhone 3GS?