I seriously don't understand why somebody would tinker around with a radio when they take it out of the box and it does not work at all. If the radio is DOA when Sorry **** happens. When companies make 50K of these at a time there are going to be a unit here and there that is DOA.
Instead of opening the radio and messing with it on your work bench and start to run your own tests, WHY I ask WHY. Just put it back in the back and take it back to HRO and be done with it and exchange it and get another new one and issue is over with.
Help me understand WHY people? Am I missing a bolt somewhere?
If all you can do is "Tinker" then your advice is very good indeed, however, if you know what your are doing you can repair things like loose connectors or ribbon cables, cold solder joints to the speaker, antenna jack, discover bad wall warts, etc.. This can save a trip of rough handling back to the repair center and then rough handling back to you.
However, your caution is well taken as the sticker on most items today reads "No User Serviceable Parts Inside" for a reason. MOST people will not have either the training or equipment to address such problems. Therefore, I only send my electronic items to authorized repair centers for that item not to the local TV/Radio repair shop.