How do i fix error 1015 on iphone 3g 4.2.1

I had tried restoring my Iphone 3G to 4.2.1 using itunes and jailbreak,i had used redsn0w(6.15 baseband) because my baseband was not able to unlock After the process,i had installed "ultrasn0w" to unlock! but After recboot it doesn't seemed to catch any carrier and then i tried to restore again using the same firmware and then the problem occurred my iphone started to give me an error 1015,by now I have used redsn0w(6.15 baseband) but it wasn’t working,then i tried tethered it was the only option on redsn0w and unfortunately it wasn't working as well.later i tried Restoring with the 4.2.1 in iTunes and lastly i tried iREB-4.0.x-4.1-RC2 with custom firmware but haven't got any success yet.any help regarding this problem will be highly appreciated.

Even i had the same error some days ago but i was able to solve it by this way.just try recboot it with a mac if you have it because i think it will boot you out of recovery and you will be able to solve it out but in case if you don't have mac try rebooting it with tinyumbrella,you can just check it out on YouTube.It would be fine after a custom firmware.

I am facing the same 3g problem on my iphone 3g 4.2.1 which is upgraded to baseband 6.16 using reds0w.In the starting some of my sms app were fro zing my phone but later it was just permanently stuck for a long time on the apple reboot and later when i tried to do a restore using itunes i got got the 1015 error,by now I have tried recboot as well as tinyumbrella which are very well able to reboot but i am always getting a message saying "connect to iTunes log". Is there any one who can help me out with this? any suggestion for this will be appreciated.

I think i have a solution for this,just try to, I have restore it to 4.1 stock firmware rather than restoring it to custom 4.2.1.though you will get 1015 error but the recovery mode logo would have been changed just try to observe it well,just don't panic seeing the error and ignore it and then use either recboot or iREB-4.0.x-4.1-RC2 to get your phone out of recovery mode,you will find the restoring bar starting again and will continue till it finishes and after getting the Iphone with firmware 4.1 and baseband 6.15 you can use redsn0w on order to jailbreak and ultrasn0w in order to unlock.I had solved the same problem with this method i hope this will work out for you all as well.

you all can follow these steps as well just Run Redsn0w 0.9.6b5 and select (4.1 or 4.2) firmware,you will get a message just click YES and then Click next and then enter the pwned DFU mode and open iTunes 10.1,now select the official firmware(4.1.restore) and proceed opening (RecBoot. _V 1.1 Run Exit.Bat) and just after it is completed Run Redsn0w 0.9.6b5 and select 4.1 firmware you will get a message,Click next but don't tick install ''update ipad basebande'' only tick ''install cydia'' and after this process is completed Again Open Redsn0w 0.9.6b5 and select 4.1 firmware then click yes for the message and Click next and then tick "INSTALL CYDIA" and "INSTALL IPAD BASEBAND",click YES for the message and then Click next and then just Follow the introduction for DFU and you will be able to jailbreak and then Extract Unlock 06.15(excluding WiFi) and then open Unlock.bat,Reboot your Device and you will be done with unlock.