Exclusive: How to Replace iPhone 3G/3GS Baseband Chip Step-by-Step Guide with Photos

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If you are familiar with DIY electronics repairs and do not mind destroying your iPhone, you can refer to the rough guide below on how to replace your baseband chip pre-programmed with baseband 5.13.04 (or lower) which can be unlocked using ultrasn0w 1.2. This method will fix your iPhone’s GPS issue (baseband 6.15.00).

UPDATE: Any AT&T iPhone can now be factory unlocked, read here to learn more. Other worldwide networks may be unlocked as well.

What you need:

  • Hot air gun
  • Solder paste
  • Soldering iron
  • Tweezers
  • Isopropyl alcohol
  • Pre-programmed replacement baseband chip (you can purchase this from us)
  • Good lighting, table etc.
  • Patience

WARNING: This is not meant for amateurs. We are not responsible for any damage caused to your iPhone. Please always practice safety first.

Editor's note: learn more by reading our ebook on starting your own iPhone repair & unlock business


1. Disassemble your iPhone and remove the logic board. See Google video here.

2. Remove the EMI shield and take note of the baseband chip marked ‘X.’

3. Cover the surrounding area of the mainboard and use a hot air gun to melt the solder that holds the chip. Ideally, the temperature should be around 290 degree C. Check out some YouTube videos here.

4. Gently remove the baseband chip from the logic board.

5. Clean up any residue left on the logic board with a soldering gun and rub the area with a piece of cotton dabbed with alcohol.

6. A close-up view of the cleaned area of the logic board.

7. Now you are ready to mount the new baseband chip. See YouTube video here for recommended ways to do it.

8. Once you have mounted the chip, wait for at least half an hour before reassembling your iPhone.

9. Turn on your iPhone and check that you now have an older baseband 5.13.04.

10. Jailbreak your iPhone if you haven’t done so and unlock it with ultrasn0w. You now have an unlocked iPhone and your GPS and other issues should be resolved. Note: This method does not make your iPhone factory-unlocked. You still have to be careful not to update it directly via iTunes.

Alternatively, we also provide this as a service. Please see details here.

Exclusive: How to Replace iPhone 3G/3GS Baseband Chip Step-by-Step Guide with Photos was last modified: July 10th, 2019 by Joe Wang

Comments & Discussion

  1. I install the new baseband chip and flash the new IOS 6 but i got the same result no wifi, no signal, no bluetooth did i miss something? did i have to reprogram the iphone? i was going to unlock via IMEI so no need of redsn0w.

  2. Hello,
    I Changed Both Chips, The Baseband and The SRAM without any luck. Infact now i don't even have a Modem Firmware on the General>About, and whats even worse RedSn0w can't do anything. When i click Jailbreak everything goes normal till it starts to upload data on the phone, It gets stuck at " Exploiting with bla bla bla ".
    Any ideas??

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