Please can anyone help ? I've tried this question in other posts but have not had any help yet. At first I just thought it was a problem with flights to and from Spain but now I notice it happens on all flights over about an hour long. At some stage approaching the TOD all my radios freeze and I am unable to change them. Even if I have preset my Nav radios to the right ILS frequency, the FMC says 'Nav Invalid'. Matts suggested posting this in the Navigation Forum, but it doesn't sound like a nav problem to me. Attached screenshot shows finals for LEPA - correct LIS frequency, both autopilots selected, course correct for the approach. All voltages/amperages on the overhead all show OK. PMDG 737 installed about a year ago - problem only started recently but i can't think of anything that may have caused it to start doing this. Should I delete the aircraft.cfg file and see if it creates a new good one , or should I uninstall the whole thing and try again ? Any thoughts anyone ?

Hi Dave,FYI: This issue has been discussed extensively in number of threads. I have included a few links below. If you are looking for further information, try doing an advanced search for "radio problem" in subject line only. These links should help:http://forums.avsim.net/dcboard.php?az=sho...ing_type=searchhttp://forums.avsim.net/dcboard.php?az=sho...ing_type=searchhttp://forums.avsim.net/dcboard.php?az=sho...ing_type=searchhttp://forums.avsim.net/dcboard.php?az=sho...ing_type=search

Guys,Problems solved I think. I'd saved a number of start up scenarios using the default cessna at various airports around the world with everything switched off (as recommended). If you do this - DON'T switch the avionics switch off because I think this is what has caused my problem. Even though on start up you can tune the radios - it will inevitably lead to the radios freezing after about an hour. Don't know why but that's the way it seems.Thanks to anyone who offered help.