Tim's 3G wallpaper was black. For him this was not a feature. He likes setting his wallpaper, though not always to my tastes.
I tried restarting his iPhone, but the problem persisted. Then I installed 4.1. That went oddly; it threw up a very cryptic and long error code about a firmware update failure, but then it completed. (Yes, I wish I'd noted the error code. These sorts of number codes are typically useless, but they're better than nothing.)
The phone seemed fine, but the wallpaper was still black. Interestingly it let me choose an image, but only the lock image changed - but there was no error code and no option to choose a background image.
After that I ran the troubleshoot gamut ...
- restore default settings
- erase all from iPhone then reactivate
- force into DFU (Device Firmware Update) mode do a new (4.1) firmware restore
I think next fix I can imagine would involve jailbreaking and browsing the file system to see if I can locate an odd image stored with some kind of permissions or lock problem. Or I could try an Apple store.
Or it could be a memory hardware error.
Then I tried restoring the phone, and I got "an error occurred ... -402636802". I then looked at the app install and it was grayed out. I knew what that was due to!
I disconnected from iTunes, turned off restrictions (App Install), reconnected, and let iTunes finish the app restore.
Still can't fix the black background (missing background image really) problem.
I figured this one out.
Remember, it's been a while since I used a 3G.
The 3G never had changeable wallpaper. Only the lock screen could be changed. Tim misled me by phrasing this as a lost feature. In reality he just wanted me to make his phone work like his parents' phones.
Well, that was certainly educational. Embarrassing too. At least it was a cold gray day.
The phone is fine. The install bug is real though.