Mấy anh em tham khảo tạm tiếng Anh luôn: ....................................................................... What is Gevey Sim? Gevey Sim, a sim created by hacker team of China, which works as a hardware based unlock(unlike ultrasn0w a software based hack) on iphone 4 baseband 1.59.00, 2.10.04 & 3.10.01. How it works? It works on the basis of IMSI(INTERNATIONAL MOBILE SUBSCRIBER IDENTITY) hack by tricking TMSI(TEMPORARY MOBILE SUBSCRIBER IDENTITY(. What is an IMSI? IMSI is a unique number containing MCC(MOBILE COUNTRY CODE) & MNC(MOBILE NETWORK CODE) that corresponds to your account in the mobile carrier's database. Sample IMSI NO:: 429 02 9806512345 (429 is MCC for Nepal, 02 is MNC for Ncell and rest part is Mobile number) What is TMSI ? TMSI is a 4 byte code which identifies Iphone before IMSI is sent and proceeded. What is the relation of TMSI to Iphone & how it works? Before apple use to only check IMSI through Iphone baseband versions to use the carrier/network. As apple found IMSI recognization process was unlocked by ultrasn0w it has introduced TMSI identifying procedure to make tough & almost impossible for ultrasn0w work to in it. Then, how did Gevey Sim Managed to overcome TMSI procedure to unlock Iphone-4? As we know, although any brand mobile is locked to any carrier of any country, it will still be able to dail 112(emergency call mode number) with Sim and also without sim.Gevey Sim tricks Iphone by using same number to get TMSI for your connection.Gevey sim is made in such a way that it's interposer rapidy cyle a list of IMSI to find an acceptable MCC/MNC combination which cheats your carrier and make it think like IPHONE 4 is factory unlocked. How to Unlock Iphone 4 with Gevey Sim? As Gevey Sim is a hardware based hack so it doesnot needs jailbreaking process can be done without any pc skills.Easy Steps are already inside Gevey Sim's User Guide, but still if you lost it here are steps for you. Step 1: Chop a small part of your sim card to fit in gevey sim card.Make it look like. <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> Step 2: Fit the cutted sim with the gevey Sim and put it on the metal sim tray. Step 3: Turn off your iphone and insert your Simcard and Gevey Sim together. Step 4: Turn on your iphone and wait for the Sim welcome menu to show and then select "accept" Step 5: At the beginning a "no service" message will show on your IPHONE, don't do anything and wait until you see one signal bar appears on the top left corner. Step 6: After you see the signal bar dial "112" and hang up within 2 seconds. Step 7: Turn on the Airplane mode(Iphone Homescreen-Settings) and then turn off right away. Your iphone will show "Sim Failure" and then "No sim card Installed" Step 8: Until the "NO SIM CARD INSTALLED" message shows up turn on the Airplane Mode again and turn it off right away again. As the "Sim Failure" shows up wait for few seconds.Network signal will show up after few seconds. Note:- If still you have no networks signal follow the procedure from Step 3.To use 3g network Data roaming option must be on from the network menu. As at current gevey sim is the only unlock beside the factory unlock(Buying a unlocked iphone or buying an unlock through <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> unlock through ultrasn0w your iphone 4 must have bb 1.59.00 either you need to save it or downgrade to it(which isn't impossible but almost not possible).So, you may problems like "No service" and no network signals problem. What are the problems regarding GEVEY SIM and where should I be aware? Gevey Sim is just like a tethered jailbreak you do to your iphone which requires to tethered it with every reboot. You should not switch off your iphone or let the battery be fully down.If you did so you need to restart the procedure as above(start from step-3). Problems like "No service" are usually seen in networks having low signals.So if you are in such networks it is better not to buy Gevey Sim until it's an emergency. You must dial and check if "112" works or not before paying for a Gevey Sim. SIM interposer will not harm your iPhone hardware but it can get your account banned from your network provider if they knew that you have spoofed your IMSI and ICCID. Its only in China that GSM companies know this loophole but still don't bother to close it, since it's product of china. Then, what is the solution for "No Service" Problem? If you get such problems after few hours or minutes your iphone was having signals through Gevey sim then see the carrier option under iphone iphone homescreen-settings. If Carrier Option(under homescreen-settings) is missing follow the procedures as in above(from Step 3). If carrier option is still there, try switching airplane off and on if it didn't work then tap on carrier option and let the carriers be loaded(searching will be seen on screen).Then select the corresponding carrier you are using from the list.If it doesnot solve your problem then follow above procedures(from step 3) again.Still if you see same problem then you got a cheap Gevey sim please return it and buy a more expensive one.