No, I haven't as yet experienced a problem like that.
And yep, sadly this seems to me that this may be the start of a power issue with your 751r receiver.
When I first read your post I initially thought that maybe it is the auto power shut-off feature which activates if there is no audio detected for a period of time. I know my receiver has automatically shutdown on occassion when I have been distracted for a while and nothing being playing, and/or a movie on pause or such like.
I remember reading it in the manual, too but that was a while ago. So after reading your post I turned my receiver on and left it on idle, and started browsing through the manual. And eventually I found it: at the end of the manual on page 38 (looking at the PDF manual - should be the same for the hard copy manual) there is the heading Auto Power Down
. And there it states that if no audio is detected for 30 minutes
then the receiver will auto power off (go into standby). I was hoping for you it would have stated 15 minutes as that could have been a possible answer to your query. But no, it says 30 minutes.
Secondly, I hoped then, that the auto power off feature might be customizable, that is, one can increase or decrease the duration of the time period before the receiver shuts down. But no, there isn't. All it has is the feature to either enable or disable the Auto Power Down.
Check in the onscreen display (OSD) and see if your Auto Power Down
is enabled or disabled (hopefully your unit won't shutdown in the middle of doing this). You will find it under the audio settings, and then the Advanced Audio Setup
. Use the arrow keys of your remote to toggle it from enabled to disabled. If you want to experiment and do some minor trouble shooting try disabling it (if it is enabled) and see if the problem still occurs. I think it won't make a difference. But if you find that it now stays on then you have possibly isolated the premature shutdown issue to that part of the receiver. Maybe.
But as mentioned at the outset, yes, I think there is a power issue. And it may be heat related in that your receiver is overheating too much - I noted your comment regarding the ambient room temperature and the unit's position so it seems to me that isn't contributing to any heat issue. And incidently if this is the case you should get a message on the receiver's display stating Protection Overload
as per the IMPORTANT message on page 5 of the manual. Mind you, that is related to playing the receiver at a very high level thus generating the heat necessary to trigger that warning. If this is the case then the receiver will also go into standby mode. But if it isn't heat related then it is probably a failed or failing electronic component.
Well, not sure if what I have typed is of use. But those are the things I would consider.
Failing all of the above (or more likely regardless of the above), then it may be a trip down to the authorised repair shop.
Hope it works out eventually.
(took me a while to type this and at 25 minutes of idle time my receiver is still on)