temporarily rolling back to original iPhone?

[alaskaflyer]

I'm still researching this on my own but I thought I'd check and see if anyone has tried something similar...

My wife's 3Gs iPhone needs to be sent in for repair due to her dropping it and some audio features now not working (I'm guessing a solder connection fractured somewhere.) It works fine in other ways so it is syncing fine, the data is intact, etc.

I kept my original first-generation iPhone when I upgraded a while ago for just this sort of eventuality. So I would like to 1) Move her SIM card from her existing 3Gs phone to this one so she can use AT&T voice/data; and 2) sync it so it will be a reasonable facsimile of her existing phone as far as contacts, profiles, settings...you get the picture.

One issue I know of us that it has been a long time since I synced my old iPhone - it's been sitting in a drawer so it will need the whichever newest operating system update that is compatable with the first gen iPhone. But do I do that first under my iTunes profile or migrate her profile first?

Anyone have any experience? Is this something which I can rely on Apple to "just make work"? It is certainly easy to migrate forward but I'm curious how "backwards compatible" the procedure is...

 

[alaskaflyer]

It appears as though since her 3Gs is running OS 4, which is not compatible with the first gen phone there may be an issue here...?

 

[flyingcheesehead]

There may be an issue with her apps. If she has apps which use API features only present in 4.0, they won't work on an earlier operating system.

Google "switching iphones" and you'll get tons of how-to information. Looks like it's mostly a SIM swap and "restore from backup" to the "new" (in this case, old) iPhone.