How to Use Gevey Turbo SIM to Unlock iPhone 4 on iOS 4.1/4.2.1/4.3.3?

This guide is for those iPhone 4 users who have bought Gevey Turbo SIM and are little confused about its working. For those who don't know, Gevey SIM is well capable of unlocking iPhone 4 01.59.00, 02.10.04, 03.10.01 & 04.10.01 baseband on iOS 4.0/4.1/4.2.1/4.3.3. I am myself using Gevey SIM to unlock my iPhone 4 and have found no noticeable drawback except i have to redo the unlock procedure if my iPhone needs a reboot.


UPDATE#1: Gevey SIM Pro: Faster IC, No Need to Cut SIM, Support Multiple Carriers
UPDATE#2: Gevey Pro vs Gevey SIM [Hands-on]
Before proceeding to the unlock procedure, let me clarify some of the widespread misconceptions about Gevey SIM:

• Gevey SIM has no effect on the battery life of your iPhone.
• You do not need to jailbreak your iPhone 4 before using Gevey SIM.
• Gevey SIM never slows down your iPhone in any way.
• Losing signal for 2-3 mins will require you to redo the unlock procedure again. Losing signals for some seconds have no effect on the unlock.
• To unlock your iPhone using Gevey SIM, you must call 112 for atleast 2 seconds. After 2 seconds, you can safely drop your call.

Steps to Unlock iPhone 4 on iOS 4.1/4.2.1/4.3.3 Using Gevey SIM:

STEP 1: Navigate to Settings » General » Network and turn OFF 3G. Keep Cellular Data and Data Roaming option ON. Make sure there is NO unofficial SIM present in your iPhone SIM tray at this time.

STEP 2: Remove stock SIM tray from your iPhone

STEP 3: Put Gevey SIM interposer in Gevey SIM tray.

STEP 4: Put unofficial iPhone SIM on top of Gevey SIM interposer.

STEP 5: Turn OFF your iPhone by pressing the power button on the top.

STEP 6: Put Gevey SIM tray along with Gevey interposer and unofficial SIM into your iPhone.

STEP 7: Turn ON your iPhone.

STEP 8: After turning your iPhone ON, you will see SIM welcome message. Tap on the Accept button to continue. At this stage, you will find 1 signal bar in the status bar of your iPhone.

STEP 9: As soon as you will tap on the accept button, you will see Searching... and then No Service message on your iPhone. Do not do anything yet. Wait while 1-signal bar reappears on your iPhone status-bar. Once you see 1-signal bar, dial 112 from your iPhone.

STEP 10: After exactly 2 seconds, tap on the End button to hang-up the call.

STEP 11: Go to Settings and turn Airplane Mode ON. Do not do anything until you see No SIM card installed message. As soon as No SIM card installed message pops-up, tap on OK button to close the message and turn Airplane Mode back to OFF.

STEP 12: As soon as you will toggle Airplane Mode to OFF, you will see SIM Failure message. Thats it! Tap on OK button to close the pop-up and wait while your iPhone unlocks itself.

STEP 13: After some seconds, you will see full signal bars in the status bar of your iPhone. Thats it! Enjoy your fully unlocked iPhone 4 with Gevey Turbo SIM :D