My Philips iPhone dock DS3010/10 charges my phone but doesn't play any music?

My iPhone 4S is iOS 6.1 and when I put it on my Philips dock it charges but doesn't play any music. I tried my iPhone on my brothers exact same dock model and it still doesn't play any music. Neither does my iPod nano on both of them. My phone used to play music on my dock before. However my brother's iPod touch works fine on his Philips dock. I'm confused because my phone also doesn't work on my uncle's iPod dock (not sure what make- not Philips though) unless it's physically pushed forward on the dock's hinge. I'm not sure whether this is a problem with Philips or Apple- or whether it's something to do with the dock connection or the software version. Can anyone help me! I've tried resetting iPhone.

Hmm… That's a tough one. I recommend going to an Apple store with your iDevices, I'm sure they have some docks on display there, try out to see if it works. If it doesn't, ask from the Genius Bar.