i am new to Philips TVs and own this one since Saturday.

Unfortunately i experience problems since then.
TV is on Internet over LAN Cable and Firmware is up-to-date.

Watching TV on cable analog or digital is ok.

Connected are
Denon 1911, PS3, Sony BDP-S350 and XboX 360.

Video is always OK, connected directly on the TV or with Passthrough via the Denon.

But sometimes (about30-40% of tries) there is a serious sound issue when switching between the input devices or between internal or external sound.
It does not matter if the devices are connected through the Denon or directly on HDMi1,2 or 3.
The issue is that the internal speaker does no sound at all, or
the internal speaker is totally blurred (like scratching on a white board).

This failure even persists after switching from the input with the failure to other input devices OR the internal TV cable receiver.

The failure is gone after turning the the TV off-on.

All devices were working on a Sony 40" LCD display and all cables were changed.

I think this is software problem, please help.

Thank you,

I think