Hi gurus, Need advice: how to figure out whether it's something wrong with iPhone itself, or I'm doing something wrong??? Story: - Bought iPhone 4 off eBay, with iOS 4.3.3 (8J2), BB 04.10.01. - Never inserted any SIM (because never had one). - Called AT&T to check whether this IMEI is blacklisted for any reason - was told no, phone is officially off contract. - Jailbroke untethered for 5.0.1 (redsn0w_win_0.9.10b4), preserved baseband, hacktivated successfully. Everything works except cell network (of course). - Bought prepaid precut US AT&T microSIM off eBay (stated "iPhone 4 compatible), first inserted into old clamshell w/adapter, activated, added some money to account, checked calls OK, inserted into iPhone - oops, "SIM error". - Figured out the prepaid SIM got locked to that clamshell, nevermind, threw away the SIM. - Took a micro-SIM that came with iPad (never used it), called AT&T prepaid cust svc, told them I lost the SIM and got another one, asked to activate - got it done. Yahoo, now I'm getting prepaid iPhone, right? - Nope. Even though that micro-sim works fine with 3 different old phones, and in iPad it gets AT&T network and shows all bars, no data - nevermind, don't need it there... But in my iPhone4 it can't find the network and shows "no service"!!! (and yes, I am checking it in a good location, all phones get full bars) (and yes, Wi-Fi works on this phone) What to do??? I am OK to buy a proper Gevey card, but why would it help if it doesn't work even with AT&T prepaid micro-SIM in US? I am NOT OK to go for contract or data plan for this phone, don't need it. And I am NOT SURE if it is OK to go to AT&T with a jailbroken/hacktivated phone and ask to check it with their SIM. I am MAYBE OK to go to non-ATT repair shop and pay them to have phone checked, in case of no other options and someone refers me to a reliable store in Boston. Can I reverse hacktivation and re-activate that phone with iTunes, does it matter? At this point, is there a way (other than full official restore and upgrade the BB which I'd rather not do), to tell whether it's cell phone receiver problem (too late to return anyway), or activation problem, or what? Please advise. Model MC610LL, BB 04.10.01, iOS 5.0.1, "Carrier": AT&T 10.0, "BasebandBootloaderVersion": ICE_2_13.