iPhone Brain Surgery

You think you’re good at soldering? Can you solder a CPU? A CPU inside an iPhone? A decapped CPU inside an iPhone? Can you solder inside a decapped CPU inside of an iPhone?

If you can’t, fear not – someone can, and we found him or her courtesy of a video that [Bunnie Huang] tweeted a while back. There’s not much information in the video, but from what we can gather it comes from an outfit called G-Lon Technology in Guang Zhou. Their Facebook page suggests that they teach cellphone repair, and if they take their repairs this far, we’d say the students are getting their tuition’s worth.

The reason for the repair is unclear, although the titles refer to a “CPU to U0301 AP31 AR31 broken repair,” which we take to refer to a boot error that can be repaired by exposing a couple of pads inside the CPU and wiring them to another chip. We’d love to hear comments from anyone familiar with the repair, but even in the absence of a clear reason for undertaking this, the video is pretty impressive. The epoxy cap of the CPU is painstakingly ground away under a microscope, then tiny tools are used to scrape down to the correct layers. Solder mask is applied, hair-thin wires are tacked to the pads, and a UV-curing resin is applied to fill the CPU’s new gaping hole and to stabilize the wires. It seems like a lot of work to save an iPhone, but it sure is entertaining to watch.

Can’t get enough of poking around the innards of chips? We’ve got decapping stories aplenty: one, two, and three that you might like. We’ve even covered at least one CPU internal repair before too.

Thanks to [Dr.Tune] for the tip.

45 thoughts on “iPhone Brain Surgery

  1. What I personally find most amazing is that in the West, we do very little electronic repair anymore (TVs, etc) but in China it’s a big deal and people actually tackle repairs this difficult!

    1. I have a Nokia N900. There is a known fault with these models where the USB port (also used for charging the phone) can become damaged and fail. There is also a known fix involving some re-soldering of the USB port to make it stronger. I couldn’t find a single shop anywhere in Brisbane (very big city in Australia) that would even consider doing board-level work on my phone to fix it. Thankfully, I was put onto the people at HSBNE (local hackerspace) and I was able to go to HSBNE on one of their open days and someone there was able to fix my USB port.

      Seems like all too often the answer for a broken phone (if it isn’t something simple like a screen replacement) is “throw it away and buy a new one” (back when the phone was still supported by Nokia, the official remedy for any phone that had a broken USB port was “give them a replacement phone” and in fact the phone I have now is my 3rd N900 after my first one got replaced under warranty because of an issue with the front camera cable and then that one was replaced for the USB port issue)

      1. It’s a culture thing. Western countries tend to replace broken items with new ones just because they can afford it, so no one bothers to do even simple repairs. I live in Poland and can’t afford to buy new stuff, when something breaks down, so I fix things. My monitor died because capacitor shorted out and chose new Pope – I replaced it with spare desoldered from old tape player board. Washing machine started to leak – I replaced a hose that costed me pennies. In western countries such faults are considered “beyond repair”. And let’s not forget “planned obsolesce” thing…

        1. That’s not true for all of us in Western countries. I live in the USA and would have done the same repairs you did for precisely the same reason: I can’t afford to replace those items.
          I can’t speak for everyone, but I seldom throw anything out without trying to repair it first. I know a lot of people around here that treat things much the same way I do. Just because the stereotype says that “rich Americans throw everything away” doesn’t mean it’s true.

          1. 2nd. I once had a neutral bar break off and short out the breaker box frying almost everything plugged in. Insurance paid to replace everything that was damaged. I was able to repair everything for about a third of the payout. Few blown caps, couple of powerboards, couple of PSUs and I was back in business. Had to buy a new microwave though :D . That thing was done (but I did try!). U.S born and raised (and poor)!

        2. I’ll disagree and say it’s a cost of living/labor issue. The time required to enact some of these repairs can get so expensive that nobody in the US could do them for less than the cost of part replacement and not be homeless. For hobbyists it’s fine, they don’t have to make ends meet with the job, but a repairman must charge a fair wage for themselves and offer their customer cost-effective options and that combo means part-replacement.

        3. It’s a $/hr thing; when you look at the hourly cost of living in much of the West, it only makes financial sense to fix the most expensive stuff (e.g. even in SF, a wildly expensive place to live, there’s brick’n’mortar stores fixing mostly Apple products.. but not much else); it’s quite rational. Sucks for the environment and other reasons, but rational.

        4. That’s definitely not a culture thing. Just because I can possibly afford to replace broken things,it doesn’t necessarily mean that I’m willing to pay hundreds of euros to replace something. Even if a simple capacitor swap or hose replacement fixes the item. I live in Austria and from time to time we have so called “repair cafes” where hackers and hardware-guys teach and show other (ordinary) people how to do simple repairs.
          And even when you are not able to repair the broken item, you will at least learn something and gather more experience for the next repairs to come.

      2. Labor is considerably more expensive here than in china. So with a guy here getting paid $50/hr (I charge way more than that) compared to a guy in china getting paid a fraction of that the cost effectiveness of repairing something like this goes down the tubes.

        1. I suspect the main reason for repair in this case is to recover data from the device. It can easily be worth more than the device itself, and even those who regularly back up can get caught out when there has been a substantial change since the last backup. (Was called to do that at work once, where a HDD failed in a data acquisition system while it was collecting data. Was able to recover all the results intact except one, which was recovered enough to be of use.)

        1. Probably yes.

          To be useful it requires:
          – Mainline kernel support for the peripherals/devices you need to use.
          – Possibly userspace support for some of the peripherals like the modem if you need to use them.

          See the following for the status:
          http://elinux.org/N900
          – arch/arm/boot/dts/omap3-n900.dts

          It also has mainline u-boot support but it’s chainloaded after NOLO: You can’t replace the stock bootloader and instead you boot u-boot instead of the kernel.

          Denis.

    2. “What I personally find most amazing is that in the West, we do very little electronic repair anymore (TVs, etc) but in China it’s a big deal and people actually tackle repairs this difficult!”

      As a repair person, I can say that this is a result of simple economics. In the West the economy has shifted to people’s time being worth more, and physical items being worth less. This leads to me telling three quarters of the people who bring a TV in for me to look at that fixing it would cost over half the price it cost new, which would now by one that is either larger, higher definition, or both. 90% of those cases would be worth doing for a hobbyist who wasn’t having to account for office rent, keeping the lights on, and keeping me fed even in between times someone has something broken. Computers are still worth having some one fix most of the time, but even there the ratio is getting narrow.

      Meanwhile, if everyone was earning the sort of hourly wages people earn in china, fixing would be much more affordable and replacing much less so.

        1. I would say that the last 20-30 items I have repaired have each been totally different and it would be impossible/impractical to set some automated robot line to take the screws out of say an Acer monitor, remove the power PCB, replace 4 capacitors and re-assemble before grabbing the next job, a HP monitor which requires a fix on the backlight driver before moving on to the Lenovo laptop requiring a new power socket or the other Lenovo laptop which is a different model but also requires a new power socket (which happens to be a totally different part) and so on…..

          Even when I worked in a factory where OEM equipment came back for repair, each fault was unique. The few occasions where particular faults became common pointed to a design flaw which was subsequently rectified.

          So even an OEM manufacturer fixing their own small range of products would find it impossible to automate something as complex as product disassembly, fault diagnosis, component replacement, functional testing, assembly and final testing.

          Automation has its place but only in mass manufacturing.

          I fully agree with the labour cost issues. I was recently asked to fix a high end gaming PC monitor that had been knocked over by his cat and had a smashed LCD and I told the guy to buy another or see if he had insurance to cover it as it was not worth fixing. He was put back by this and did not believe me so I had to show him my supplier wanted $384 for a replacement LCD panel to be shipped from the USA and they he would have to pay me for fitting it or he could buy another new monitor for £199.99 instead.

          Also, some things are just designed to throw away. I have at the side of me an Anker 5-port USB power adaptor that has 4 of the 5 ports not working and know it would be an easy fix but have replaced it as they are only £20 new. It is glued together and just getting to the PCB will cost me more in my time than the £20 before I even took a soldering iron to it..

          1. As well, technology is changing so fast that it seems like new chips/components/etc. are brought out almost daily, which makes having a supply of them on hand pretty much impossible. …which means that, once you find the problem component(s) (assuming you have the test equipment to identify them in the first place), you need to find a supplier who is willing to sell you one of something that they usually only sell in 10K quantities. …and you need to have a selection of both SMD AND through-hole versions. Oh, and did I mention that just finding schematics of most products has become almost completely impossible, even for official service centers?

            AAAAAARGH!!!!! pant pant

            Okay, rant over. As you were, citizens.

          2. I agree DeadlyDad,

            Got given a faulty Bush DAB radio which had 2 blown SMT audio chips. They were <30p each but had to buy 30 of them from Alibaba. I keep looking on eBay for cheap faulty ones to use the rest of the chips up and flog on.;-)
            To top it all off, got given another (slightly newer model) Bush DAB to fix with the same fault but it used a different single SMT amp. Had to buy 25 of that type so looking around for another 24 faulty radios.

      1. Someone this skilled could probably automate parts of the repairs (find all screws and unscrew them for example), so she could fix more people’s devices at the same time and hence cost less than a replacement device…

        1. No, they could most likely not. Unless you have access to some sort of intelligently learning repair robot that is unknown to me at this time.

          Usually each repair is an individually different task with an individually different part in an individually different enclosure. Automation does not make sense for unique occurences. Automation strives on scale. Which is not availabe in these cases.

          But please, enlighten me. Tell me how to automate the process of, say, taking apart a laptop where screwes of different sizes and types need to be done in an exact order to get to the part you want to repair. Or how a robot will intuit that the screws in some enclosure are hidden behind rubber that needs to be peeled off first.

          1. screwes = screws obviously

            Also: To train the robot to take apart the first laptop would take longer than dpoing it yourself, which only would pay off if you’d repair the same type of laptop a given number of times. Which is unlikely considering that there are n types of laptops out there and they become obsolete within a very short timeframe and are replaced with more new types of laptops.

    3. Sony hdtv got for £0.20p, the cost of a pack of resistors and five mins of my time.
      Scrap bin sourced HP AIO with faulty touch: upgraded from i3 to core i5 (Too many at work thus free-for-all), cost £0.00
      Dell laptop (core2duo fans usually off thus is a laptop) 6 to 8 years old previous owner(s), had for about a year: £20
      APC SMART-UPS 1kva another scrap-dive, swallen batteries (bad chem), 1.5h strip/rebuild: £10.80p in time taken

      So-on and so-forth…..Except pushbikes, where I sometimes splash out a bit more than I’d want to because of various factors.

      1. forgot to mention: The replacement UPS batteries were from a stock left after a lost contract (almost all of the BACK-UPS failed with a Kaboom type Epic-fail and the customer thought we were playing them).
        Grabbed the batteries before they sat too long.

        Oh and the time-price figures are based on a rough wage amount (personal time being measurable against my wage rates as though that is what I could of earned if over-time was available at a 1:1 pay rate)

    1. Too true. The missus was upset last week because her Jellyfish have stopped swimming in her jellyfish lamp. £40 for a replacement because of the seized motor due to corrosion.
      I would have had to get the Dremel to it to get to the motor as it was well glued together, find a replacement motor from China (I looked at the usual suspects, Mouser, Farnell, RS, Digikey but none had the part), wait for this ‘quality Alibaba’ replacement being delivered, buy some suitable glue and carefully re-assemble and make it water tight again.
      I anticipate it would take me well in excess of a couple of hours (including sourcing the motor on the web) and I charge MUCH MORE than £20 an hour to my customers so am better off doing my day job.

  2. I think part of the reason us in the West don’t do repairs like this is that the tools necessary to do so are prohibitively expensive, because they are all made in China and have to be imported. When you live where both the gadgets and tools needed to fix them are all made, it becomes more economical to do repairs like this.

    I’d love to have a microscope, fine pitch soldering tools, and all the other necessary stuff to do this kind of tinkering. However, all of that stuff adds up to far more than the cost of a used replacement device if something breaks, and I don’t tend to break things often.

    1. Partially correct…
      The gear they use is often made in Germany or USA – quality instruments.
      Chinese version exist of most machinery of cause.
      But the real kicker in china is the fact that you are able to find people that #1 have the equipment and are #2 willing to use it for small amounts of money or let you use it.
      How many people do you personally know that work in silicone manufacturing that you can ask? In Shenzhen chances are way higher…

  3. I’ve had a go at repairing internal pcb traces in an iPhone and despite my best efforts the sub millimeter traces were just too difficult to isolate for me .

    Yes fault finding is the hard part but doing that kind of work is stilll unbelievably difficult with out plenty of experience.

  4. It seems like there was an awful lot of collateral damage. The ram chip he had to grind through is obviously not connected to any of the dozed balls in the corner, and there may be shorting of the copper layers on its carrier. Then on the cpu carrier he scraped away dozens of traces… And finally he just connects the pads to some decoupling caps on the other side of the board? Does anyone know how this repair is supposed to work?

      1. The mystery continues, the repair you linked connects to different balls that are closer to the corner. That repair seems ‘more’ believable, since it looks like it really is the 0th and 1st ball in from the edge (as opposed to the ~5th shown in this video) so much less of the chip would have been damaged.

  5. Just another data point – I’m in the US and insist on repairing everything I own rather than replacing. Drive one car with 160K miles, and our other has 80K but is 30 years old. Cars are easy – I can find parts. All electronics that fail get fixed if I can get parts. Thing is – I’m finding my list of suppliers for parts shrinking (semiconductors, opto, & mechanicals like belts). More and more I end up on eBay. Some things get hacked into working by buying a spare busted duplicate for nearly nothing or improvising, some get repurposed or parted out.

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