I bought an i phone 3G, 4.0.1(unlocked) from ebay. When i inserted my sim, a message "No SIM" showed up and i tried many times. Is it necessary to turn off and on before and after inserting SIM?Do i need to activate it again? Power button doesnot work,as the seller mentioned in his/her post, may b jammed or whatever the reason. But i thought i hav nothing to do with power button 'cause it will automatically turn on connecting it with PC, so i decided to go with it. Then i reset the all settings including network setting. Now I have no clue it has gone to default stage or still can function as unlocked??

To sum up, how to fix 'NO SIM' error? is it still unlocked after resetting all settings?? how can i turn off without using power button? is it possible to do so by syncronizing with PC?

your help will be appreciated.

hahahah  brooo , why did you reset all the setting ?Now you have to unlock it again . 4.0.1 can easily be unlocked . search in Google you will find it !

as garib_manche said u will have to unlock again!!!! well just did it yesterday and had same problem!!! but firstly try with resetting the network setting and if it doesn't work!!! then probably you will probably need to upgrade the baseband!!! what firmware is your iphone 3g? if it's 05.14.02 then u will have to upgrade!! hit me up if you get any problem!!!

Thanks Garib manche and Alece. My firmware version is 4.0.1 so do i need to upgrade it to jailbreak?  i m planning to jailbreak with redsnow, i dont know it gona work or not? i read somewhere, at certain instance home button and power button has to be taped is that true 'cause my power button does not work. If u hav done it recently, share me some problems that might occur.  

dude m talking about the modem firmware!!check what firmware are u in ??it's just that if it is in 05.14.02 u will have to upgrade the baseband. one u said 4.0.1 is software version. u can go to store to fix the power button will cost like 40 bucks i think but if u want to do without fixing it !!using power n home is about getting ur phone to DFU mode so that u will be able to restore and downgrade. here it goes : download the link n follow the instructions:(not tried this but i guess it works)

Hey alece

I tried that way to go to FDU mode but it didn't work out. I mean , i got nothing. Then i tried other method as below but it didn't work either.Bytheway my modem firmware is 05.13.04. do i need to upgrade it to higher baseband. Any other way to do so except apple store as the last resort

TO ENTER YOUR IPHONE INTO DFU MODE IF POWER / HOME BUTTONS ARE BROKEN

#1) Download the iOS firmware that corresponds to your device.
#2) Rename the extension of the file that you’ve just downloaded from .ipsw to .zip.
#3) Unzip / unpack the file (yes, those .ipsw firmare files are in reality just zip files!)
#4) Browse to the directory Firmware\all_flash\all_flash.m68ap.production. There you should see a file called LLB.m68ap.RELEASE.img3. Erase it. There’s also another file there called applelogo.###.img3 (the ###’s are uniue to your device) – this file should be renamed to LLB.m68ap.RELEASE.img3 (the name of the file you’ve just erased).
#5) Browse to the directory Firmware\all_flash\all_flash.n82ap.production. Locate a file called LLB.m82ap.RELEASE.img3 and erase it. Again locate the file applelogo.###.img3 (the ###’s are uniue to your device) and rename it to LLB.m82ap.RELEASE.img3 (the name of the file you’ve just erased).
#6) Save your updated zip file.
#7) Rename the zip file’s extension back from .zip to .ipsw.
#8) Open iTunes.
#9) inside iTunes hold down the “ALT” button and click on “restore”.
#10) Select the .ipsw file you just worked on and let iTunes to its work

First thing, do not upgrade the baseband unless there is unlock available for them. (There wasn't any two weeks ago). Your current baseband is easily unlockable.

Second, do not upgrade to iOS 4.2x if you are not sure because it upgrades your baseband making it harder to unlock. iTunes will show you the upgrade option. Just ignore it.

Download latest redsn0w. Download .ipsw file for your version of iOS (4.0.1?). Run redsn0w. It shows you easy steps to jailbreak your phone. 

Thanks guchhachor, nice name, reminded my childhood. Any way my problem is  power button doesnot work in my case so i can not go to recovery mode while jailbreaking n i m trying to put iphone in dfu mode before starting jailbreaking. do u know any way to do that??  

Lapid ,

 If you can get an Att SIM from any of your Friends insert that to activate the iPhone. That would be the easiest method.

If not, try this to activate the locked iPhone (hactivate). It solves the battry drain issue and push notification issues. Already jailbroken means you have cydia .

           Add http://repo.bingner.com as a repo in Cydia

           Install "SAM" and "SAMPrefs"          

          Go to Settings > SAM and touch "De-Activate iPhone"

           Activate with iTunes (If iTunes says invalid SIM, you will need to manually select the appropriate carrier under one of the methods besides "Automatic" and click on a SIMID.)

 

hey bro!!!