how to break your baseband and how to fix it
i did an ieraser with 4.x-secpak , and the iPhone went disfunctional .
iphuc works. phone cannot boot with fsboot. then did a DUF 1.1.1 upgrade,
failed, then did a DUF 1.0.2, succeeded. i think it's a virgin now.
to test and confirm
now to broke 1.0.2's baseband. ieraser with 4.x-secpak in 3.x bb firmware
DUF upgrade to 1.1.1, failed.
then in restore mode, use itunes to upgrade to 1.1.1 again, failed.
iphuc to issued a "cmd fsboot", the iPhone booted, but bb have not upgraded, main screen reads "Repair needed, cannot make or receive calls." look much like people with anySIM issue.
DUF upgraded again, failded.
tried DUF 1.0.2 upgrade, succeeded. bb fixed.