No sound after IOS 4.1 update

What have you tried so far? A 'reset', a 'restore'?

I'd suggest a 'reset' first (because it's least intrusive): press and hold sleep/wake and Home buttons together and wait until the Apple logo appears before releasing both and then wait until the Home screen appears.

(Before anyone says, I know the update process 'ends' with a 'reset', but you have to start fault-finding from a definite known-point)

Message was edited by: RestlessFool

Set the ring/silent switch on the side of the phone for sound - red dot NOT showing.

Try playing some ipod music through the speaker, and then repeatedly plug/unplug a set of headphones until, hopefully, the speaker sound comes back. Worked for me once.

I Have the exact same problem with my 3Gs

Same problem w/ iPhone4

...and it just mysteriously started working again. I don't know what happened. Maybe it needed time to rest.

I did have my phone set to vibrate (manual switch) and turned that on. Maybe that did it. Worth a try. I'm a happy camper now.

I am having the same problem with the upgrade and when I reset the phone it made a weird hissing noise for about 3 seconds and then no sound. I tried a couple other things like a restore, but it won't allow me, a settings reset, the headphone thing suggested. Any other ideas??

No sound for my iPhone 3G after iOS 4.1 update! Restored back to 3.1.2. Still no sound! (befor the 4.1 update, everything was fine).
Then I reset all settings, sound came back. But then iPhone started to freeze randomly, with increasing frequency to the point I needed to restore again. This time back to iOS 4.1. And guess what - no sound! Resetted all settings. Still no sound.
Key points:
* sound loss is software issue that came with iOS 4. (i was able to get sound back after settings reset but only on iOS 3.1)
* iOS 4.1 makes iPhone unstable both on 4.1 and earlier versions.
* restore has no effect (I never restored from backup, started as a fresh phone)
* iOS 4.1 destroys your iPhone 3G

Possibly rolling back an update didn't exactly do your 3G any good? Rolling back to an earlier version is not supported. These sound problems are almost always caused by the phone being stuck in headphone mode, or...yes...having the slient switch on and not realising (I'll bet we've all done it at least once.....).

Exact same problem!! Only thing I can add is that I noticed the speakers intermittently emitting a hissing sound along with what sounds like data TX noise from a modem. I can't get the sound to stay on for more than a couple of minutes between rebooting. Very annoying.

Hey, what do you know...I was browsing the other forums and someone suggested plugging and unplugging the headphones and turning the phone on and off. I did this and then I had a good fiddle with the controls and - magic - they are working again. So maybe mechanical rather than the OS?