Tuesday, 4 September 2018

Upgrading my iPhone 6s to 256GB

In this lengthy post, I will share on how I got about upgrading the storage on my iPhone 6s to 256GB, which might be helpful if you're considering doing the same.​

So, why did I want to upgrade the storage myself?

Here my long story begins. TL;DR, my iPhone was slowing down and running out of space.

Last year, I installed an aftermarket high capacity battery from China (its legit, it did help improve battery life) to replace the old failing one. Following that, I heard about the throttling issue on iOS 11 and thought the high capacity the battery is showing might be interfering with iOS, making it confused and in turn throttle the CPU.

However, after the throttle issue was fixed, I still felt that my phone was kind of slow, and thought something else must be causing the slowdown. I did some research and found that larger capacity iPhones had a faster nand, and that the performance of flash storage tends to degrade at about 70% full.
At that point in time, I only had about 10GB of storage left on my 64GB iPhone, which equates to about 84% full. It seems that a larger capacity flash chip was the cure for my slow phone.
I looked around and found a mobile repair shop at Sim Lim Square that offers a service to upgrade the iPhone storage to 256GB, and it costs S$159 at the time of writing. (Fun Fact: iirc, at the time of launch the 6s had a maximum configurable storage of only 128GB.)

As a teenager, that seemed a little too costly for me, and felt it could be cheaper if I did it myslef. I came across a YouTube video by Strange Parts showing how he did it. His video convinced me that it would be possible for someone with little smd rework experience to successfully upgrade the storage on an iPhone. I went to find the tools he used on taobao, a popular e-commerce platform in China, and found the programmer for the nand flash to be prohibitively expensive for it to be viable for me. It costs around 1600 yuan, and that itself was more expensive than the repair shop option.

However, as I was looking through prices of the programmer, I stumbled upon sellers who sell the nand flash alone and they advertised that they are able to program the nand for the buyer. Following that discovery, I did further research and found out that you just need the model number, imei, WiFi and Bluetooth MAC address to be programmed into the nand for it to work, and there isn’t a need for the seller to have access to your device to program the required information.
However, as taobao sellers are mostly in China, you’d need to communicate in Chinese with them if you'd like to do the same. If you're interested to shop on Taobao and do not know how, you can check out my other blog for some tips on how to do so.

With the programmer being an optional item, it is now possible for me to do it myself at a price lower than what is offered at the local repair shop.

The Process


Firstly, I bought a few iCloud locked 6s boards for practice, before buying the actual nand flash for my iPhone. As I already had a hot air station and tweezers, the only tool I bought was a cheap Xacto knife to scape the adhesive away from the perimeter of the nand flash, some flux and a roll of wick. In the end, I practiced on 4 iCloud locked motherboards before moving onto my own iPhone. At that point in time, I intended to buy a second hand 16gb one to try but as I was on a budget I decided to risk it and change the nand on my main phone.

In online guides, they recommend restoring from a new firmware before doing the upgrade but I did not feel it was necessary. I however did deactivate find my iPhone to avoid any activation issues. I'm not sure if it was necessary to disable find my iPhone, but that was what I did and it worked out in the end.

The removal of the nand went smoothly and I did not pull any pads. The chip I bought was pulled from another iPhone so it had some black underfill on it. It was pretty hard to clean it properly and I did not manage to solder it correctly on the first try. When restoring, iTunes gave me error 4013. At that point in time, I was getting worried that I had bricked my phone for good.
Not willing to give up, I tried re soldering it and luckily my anxiety did not make me mess anything up and I managed to get it soldered properly eventually.
During the process, I was a little conflicted on how to solder. In some videos I saw online, they wicked the solder off the pads while others just went through the pads with a soldering iron to tin the pads. I can't exactly remember what worked, but in my opinion it would be safer to try without the wick first as you'd be less likely to tear out the pads.

Then, after restore I faced another problem. Touch ID wouldn't work when during the activation phase. I thought it would resolve after I restored my data, but it didn't. I then thought it might be the issue with the programming and I thought I would need to solder back my old chip for it to work, and my failure on the first attempt gave me some ptsd and I was reluctant to solder the old chip back again. I proceeded to ask the seller and turns out I made a dumb mistake - I did not plug in the home button when restoring. Touch ID finally worked after another restore, but that meant I had to wait for all the apps to reinstall for the second time. Not a significant mistake, but it would've been good to avoid had I known initially.

When restoring my data, the iPhone picture in iTunes became gold (my phone housing is silver). I guess the nand chip seller didn't program it as I forgot to tell them what colour my phone was. I initially thought they were able to find out the colour using my imei, serial or model number. It turns out they won't know unless you tell them, I guess.

After the storage upgrade, I felt that my phone was significantly faster, and a disk speed test I did before and after the upgrade reflected the change.


Old 64GB Speed

After upgrading to 256GB

Amount I spent in total:

iCloud locked practice boards: 240RMB (60 each)
256GB used nand chip: 203RMB (prices have since gone up)
Xacto knife set SGD1.49
Flux SGD3.44
In total i spent less than S$110, mission accomplished! Plus, I get to keep my old flash chip as well!​All in all, I managed to gain experience in hot air soldering and save over S$40 in the process. I'd say it's pretty good.

Should you decide to do the same, here are some things to take note of:

  • You should be comfortable opening an iPhone and removing its motherboard
  • Definitely definitely get a few motherboards to try on, if you go straight on its likely you'll ruin something. I've ruined numerous iPhones in the past and had put off the idea of upgrading the storage for quite a long time as I was really scared I would brick my phone
  • When restoring the firmware remember to plug in the home button to ensure Touch ID gets activated
  • Optimally do it on a spare phone so it doesn’t disrupt your daily usage if it doesn’t go smoothly
  • Shop on Taobao instead of AliExpress if possible, as the prices are usually better
  • Buy a brand new flash chip to make your life easier if your budget permits. You wont face issues with alignment with uncleaned underfill form used ones
  • From what I can tell when communicating with the nand flash sellers, they generally do not like selling to people who do not have any experience(like me), so you'd have to 'act' like you know what you're doing. It is possible they might refuse to sell it to you if you let them know you have little to no experience as they feel it would be more likely that you would accidentally damage the chip and blame it on them and get a refund. I guess it might be because they had numerous experiences of people spoiling the flash chip and blaming it on them. I can't be really sure though, but that was what I could tell based on my experience.