iPhone X Suica Problem a Design Flaw?

1️⃣ iPhone X Suica Problem Q&A Exchange Guide
2️⃣ iPhone X Suica問題Q&A交換ガイド (Japanese)
3️⃣ Apple Denial and iPhone X Users
4️⃣ iPhone X Suica Problem Index


I know, I know, John Gruber says question marks in titles are bullshit but Japanese iPhone X Suica users are asking: is the iPhone X Suica problem an Apple design flaw? Is this the iPhone X dirty little secret?

Since covering the issue since December 2017 only one thing is clear: there is nothing clear about the iPhone X Suica Problem. It looks like a software problem but also shows signs of being a hardware flaw. The one consistent aspect is that iPhone X NFC performance is unreliable compared to the rock solid NFC performance of iPhone 8/8 Plus and Apple Watch Series 3.

It’s a problem in Japan because transit cards like Suica require much higher performance than low performance EMV contactless credit cards. Transit gates are not cash registers. EMV was developed for slow pokey credit card payments at your local supermarket, not whizzing through a transit gate at Tokyo rush crush hour. This is why EMV sucks at transit.

iPhone X Suica Problem Solved
yuya-310 is a happy iPhone X Suica user.

I did not give serious thought to the ‘iPhone X Suica Problem is due to an Apple design flaw’ theory until yuya-310 reported that exchanging iPhone X fixed his Suica problem and that Apple Pay Suica performance is suddenly and consistently as fast and responsive as iPhone 8 Apple Pay Suica performance.

In that post I wrote:

A few things to consider:

  • iPhone 8/8 Plus do not have the Suica problem
  • iPhone 8/8 Plus/iPhone X all use the same NXP NFC chip
  • The iPhone X OLED screen and battery are considerably different from iPhone 8/iPhone 8 Plus
  • There are separate iOS 11 builds, one for iPhone 8/iPhone 8 Plus and one for iPhone X

Because they all use the same NXP chip and because iPhone 8/8 Plus do not have the Suica problem, we can eliminate the NXP Chip, Mobile FeliCa stack and Suica stack from the iPhone X Suica problem matrix. This leaves us with the different screen, the different battery and the unique iOS 11 build of iPhone X. The screen or battery or something else might use slightly modified parts and revised drivers that are different from early iPhone X production units.

I asked an NFC expert for an opinion, his answer was very interesting:

I don’t have an iPhone X to test, but since it seems to affect Type A (China Express Transit Beijing and Shanghai) cards as well it sounds like an antenna specification problem, an interaction with other components in the device, or an RF routing issue on the phone’s motherboard, which is considerably more complex than the iPhone 8 models.

Another New Theory
Based on yuya-310’s exchanged iPhone X Suica experience and the above motherboard information, my new theory is that the iPhone X Suica problem is a motherboard design problem that is already fixed with a small but important revision tweak to the iPhone X motherboard. A ‘Revision B’ kind of thing that finally brings iPhone X NFC performance in line with iPhone 8.

I believe that Apple’s inability to fix the iPhone X Suica problem despite multiple iOS 11 updates is proof of a iPhone X NFC related hardware problem: if it was just software it would be fixed by now. I think events will play out in the following ways, in order of possibility:

  1. Short term scenario: Apple will not admit there is a iPhone X NFC hardware issue but will quietly swap out problem ‘Day 1’ iPhone X devices under warranty with a ‘Revision B’ iPhone X.
  2. Best long term scenario for Apple: iOS 12 has a workaround fix for pre Revision B ‘Day 1’ iPhone X devices. After iOS 12 ships the iPhone X Suica error problem is finally fixed for everybody. NFC performance on ‘Day 1’ iPhone X devices remains sluggish and less robust than Revision B iPhone X but is ‘good enough’.
  3. Worst long term scenario for Apple: iOS 12 does not fix the iPhone X Suica problem Apple admits the iPhone X NFC flaw and issues a replacement program. Every Day 1 iPhone X user gets a Revision B iPhone X replacement.
  4. Least likely scenario: iOS 12 or a iOS 11.4.x update fixes the iPhone X Suica problem, everything works great across the board on Day 1 iPhone X and Revision B iPhone X. I don’t see this happening.

When iOS 12 ships the new iPhone models will have been announced and everybody will have moved on from iPhone X. Whatever the outcome, Apple’s complete silence and non-action regarding the iPhone X Suica problem has left iPhone X Japanese customers saddled with an inferior product that does not work with Apple Pay in Japan.

Apple has yet to do right by Japanese iPhone X customers. This is sad, and inexcusable.

Advertisements