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

Hello there! If you are new here, you might want to subscribe to the RSS feed for updates on this topic!

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.

German iPhone jailbreaking website re-posted this article.

Share this and be awesome!

Comments & Discussion

  1. Is the chip ready to be soldered on the board or do I have to re-ball it? I don't have the equipment to do that. Thanks

  2. If I provide my current IMEI (in case it can't be retrieved from the ship) would I be able to order a chip with that IMEI installed? (I can provide photo evidence of IMEI and Serial on the sim tray). I'm on a UK carrier and I need my old itunes back-up :(

  3. I have a CSI 825A hot air station, solder paste, various solder balls etc. and 2 iPhone 3G's, one is blocked, one is water damaged and totally shot. I want to have a go at this myself as my soldering skills are pretty good in general but I have a question.
    I tried to remove the BB chip on a 3GS motherboard (another broken board) for practice using my heat gun on 290C with air flow at 60 and it would not budge after ten minutes! I noticed some black stuff around the chip, is this a resin glue? If so does it need to be removed first and if so, how?
    I continued on with it eventually increasing the temperature to 410C before the little bastard gave up the ghost and came off, also taking half the BGA pads off the motherboard as well! I knew it was doomed to fail long before this happened but it pissed me off and was only a test run anyway.
    Is there a method to this?
    Any help gratefully received.

  4. Hi,

    would it be possible to replace a iphone 3gs sram chip (same problem no baseband, no wifi, no service), with a wather bricked iphone 3g sram chip?

    What do you recomend?


  5. Anyone tried actually doing this? I have a CSi 825A hot air station with all the solder pastes and wot not and have re-flowed many chipsets in the past but this I just cannot succeed at.
    The main issue I feel is that the baseband chip, along with almost all of the other chips (not just in Apple products either) are 'glued' with some type of hard, not easy to melt epoxy resin as well as being BGA soldered.
    I notice the OP doesn't even appear to use a pre-heater (which I don't have either) and doesn't state anything about it being almost impossible to remove without damaging either the chip or the motherboard or both. Unless I am doing something drastically wrong, which I seriously doubt I think it fair to say that anyone attempting this will ruin their phone. Please do correct me if I am wrong…
    Also using the airgun at 290C is pointless as it will not melt the solder. I used the airgun at 350C which just about worked after an hour of picking round the chip edges trying to remove the resin with glowing tweezers!
    I still had to apply some force to initially 'crack' the resin on the underside of the chip before I could lift it and with that pulled 4 of the gold pads on the motherboard (good going actually) and killed it! Not that there was a definite chance it would have worked anyway after 350C for so long.
    It was a dead 3GS board anyway that I was testing this on and lucky I did. I honestly believe anyone trying this will only end up regretting it.

  6. You Tube doesn't show you anything about the 'under fill resin' which is different and as far as I am aware can only be removed successfully with a rework station.

      • Well the rework station to remove one of these retail at around £800GBP+. Even if you have one it is not removed in the 'normal' way and takes much longer than any other standard BGA chip. I watched a video on doing it with a premium rework station and it involved mapping out the temperature range of the infra red lamp and positioning the motherboard in a certain place – a right song and dance!
        If you removed yours with a hot air station and you didn't get a phone that did not get it's under fill correctly (if that even happens) then I tip my hat to you Sir!
        Just to clarify, for those wondering why it is stuck so well; It is not because the chip get's hot and is prone to BGA solder cracking. It is because 'they' don't want you to be able to replace it!

  7. Hi, thanks for making this guide. Can the baseband chip be replaced without worrying about the imei etc? Does the chip need to be programmed before installation? I am in the UK and can buy the chip but am unsure about programming it etc.? Hope you can help. Thanks again

Leave a Reply

Your email address will not be published. Required fields are marked *