No audio on HD only

[gdmm]

Sudden problem, all HD channels only.

When I select the audio button the remote, there are two options; 1 MPEG, 2 AAC, which is the default/selected one.

When I select MPEG, the audio comes on, but as soon as I switch channels I get no sound again.

Not sure how this has happened or how to correct it.

Any offers?

[birdman]

Try
Menu -> Setup -> System -> AV settings

and set AAC downmix to yes?

[gdmm]

Dolby and AAC downmix are both set to yes.

PS

Thanks for the response.

PPS

My other idea is to set Auto Language > Prefer audio track stored by device, which is currently set to Prefer AC3 track.

[gdmm]

Ignore all that! A restart seemed to sort it out.