Accessory not optimized for this iPhone

[NatPro]

I have an iPhone 4, after a small drop i now get the message that this accessory is not optimized for this iPhone.
The thing is, there is nothing attached to the phone, but it says this.
I also have no more sound coming from any of the speakers, so I can't make phone calls, listen to music, nothing...

When I check the sound in the settings, I can hear the ringtones, but no message tones..

 

[Cooolpenner]

Try a hard reboot (Hold down home+sleep button till the apple logo apperears) or restore it.
If this doesn't work, it's a hardware problem. You can try to get a refund, but I don't think apple will give you one ...

 

[NatPro]

I'm pretty sure it's a hardware problem.
I think I got it to work now... a quick love tap and it's sorted. Pretty dodgy

 

[ckurt25]

Can you tell by visual inspection that it's been dropped? If the answer is no and the problem comes up again, take it to Apple and see if they'll exchange it. Don't mention the drop though.

If you can tell from a crack or a scuff, they might not be as willing to exchange.

 

[BrianBaughn]

What about headphones...are they working?