After spending 30 minutes figuring out what needed fixing on a friend’s freshly updated (and no longer working) Softbank iPhone, I figured I would commit the instructions to this blog, for all the hapless gaijin out there, trying to figure out why their iPhone suddenly stopped working.

This post is purely intended for a Google audience, so please skip if you are a regular reader with none of the aforementioned iPhone issues.

After updating his iPhone to iOS 4 and upon coming back from a trip abroad, my friend found his device unable to connect to any website or mail server. Calls and SMS worked, but not data, except when connected to a wifi network. Stranger still: putting the SIM card in another phone, made it all work again (indicating that the SIM and all subscription services were fine). No need to mention: Softbank support was thoroughly useless in helping with that, merely suggesting it was a hardware problem and the phone had to be changed.

It wasn’t, of course.

Apple’s iOS 4 update shipped with a “bug” of sorts (possibly intentional) that, under certain conditions, will remove your current, valid, “APN settings profile“. Without this profile, your phone has no way to access the data plan provided by your operator. You need to restore valid Softbank APN settings.

There are many ways to fix that on the iPhone, one is to use the brand new iPhone Configuration Utility, an even faster one if you have access to a Wifi network, is to connect to the following address from your iPhone (using Wifi, since 3G doesn’t work): http://www.unlockit.co.nz/

Click on Continue > Custom APN.

Then, depending on the actual colour of the SIM card Softbank put into you phone (silver, for older phones, black for recent ones), fill up the form using these info:

For black SIMs:
APN: smile.world
Username: dna1trop
Password: so2t3k3m2a

For silver SIMs:
APN: open.softbank.ne.jp
Username: opensoftbank
Password: ebMNuX1FIHg9d3DA (unconfirmed)

Then click on Create Profile, click Install on the screen that comes up. You should be done!

Happy browsing.

PS: the reason the iphone OS update screws up this setting in the first place seems linked to past attempts at jailbreaking your phone… Apparently, even if you subsequently had your phone properly reset to non-jailbroken factory settings, the mere fact that you once had it jailbroken is enough to trigger that bug during the update. The old adage about malice vs. stupidity applies here, but it is hard not to think that this could be somehow deliberate on Apple’s part.