Now, try doing a restore from iTunes. If you chose to upgrade to iOS 4.0.2, then you lose the ability to jailbreak it through jailbreakme.com as 4.0.1 is the last firmware that is supported.

Try disabling 3G mode and then insert the SIM. If that doesn’t help, go into the carrier menu and see if the phone is actually able to see and display the list of carriers. Then manually select Airtel and see if that works. As a last resort, you can try toggling Airplane mode a couple of times.

I bought this iPhone 4 on Aug 8′th from S’pore.Its a Singtel handset and is Unlocked(Ps: Locking a handset is illegal in S’pore).I am in India and on Airtel.

I first cut my Sim to Micro Sim size perfectly(Using sim cutter),then I connected it to iTunes(Latest Version), then the activation process went on but displayed an error which i dismissed in the spur of the moment but the whole process went on i got a “Waiting for activation” message, though iTunes carried on with syncing data and finished fine.And of course “No Service” at the top.

2 Hours into the process I was still waiting at the “Waiting for activation” pop up.I started getting restless so I began using my “precious”.Beautiful device I must say(Wont say phone as I still cant make calls with it:-), Funnily, WIFI was working perfectly(all other features were working fine actually except the network ones) Then I ended up opening Jailbreakme.com and successfully jailbroke the handset and followed it by unlocking it with Ultrasn0w 1.1-1.

All this before I completed activation.Then after about 5 hours(Post syncing with iTunes for the first time) I got the “Your iPhone is activated” message.But guess what?, still “No Service” at the top left of the screen(And I cannot make calls,texts,data etc so its not the makeitmine issue”).

I tried switching off the handset,”Reset all settings”,”Reset Network Settings”,”Airplane mode On/Off” restoring handset to 4.0.1(holding shift and selecting downloaded 4.0.1 firmware as apple was providing restore only to 4.0.2).

Jailbroke and Unlocked again,Between all of this I also managed to save my blobs in Cydia(Just so that I can restore back to 4.0.1 from 4.0.2 if I upgraded).But No..My phone simply shows “No Service”.

It reads my number fine(Airtel India), It shows my carrier name and one signal bar every time it activates(For about 2-3 seconds) and goes into Searching..and then “No Service”.

It has been 3 frustrating days now, and as a final try, I upgraded my phone to 4.0.2(Something is better than Nothing) but same issue.”No Service”

Now comes the most cliched line of every apple user “Can somebody please help Me ?”