iPhone 5 - sound doesn't work

[GammarusPulex]

Hi there,

over night my iPhone 5 seems to be sound sick...

What still works:

• ring tone by incoming calls
• alarm clock sounds
• sounds by hands-free talking
• the test sound during the sound volume setting


What doesn't work since the day before:

• no music sounds
• no video or app sounds
• no key or unlock sounds


What already tried:

• update to iOS 8.1 with backup
• reset as new phone
• reset with DFU Mode as new phone
• check the 3.5 mm for dust


So... nothing of these actions work.

Anyone has a idea what I can try even more?


Thanks a lot
Oliver