Onkyo 797 audio start problem

[jabch]

I've now owned this 797 for over 2 years & have been really happy with it until now (and except for the audio pop fix needed, which Onkyo went out of their way to take care of).
Last Saturday morning I turned it on - and no sound. Checked the settings, connections, etc. but could not find anything wrong. Then finally the sound came on and everything worked fine.
But since then, everytime I turn it on, there is no sound, but eventually after a several minutes, for unknown reason, the sound comes on and everything seems to work fine.
Anyone have the same experience or ideas of what is going on?

Thanks for all ideas & suggestions

 

[audioman00]

just an educated guess

Sounds to me like the power transformer inside the unit is having a hard time supplying the current required to arm the second relay that runs the amp stage. in other words, you most likely must get it repaired by a technician. I do have one question for you though, When you power the unit on i'm sure you hear one "click" but what about the second? Does the second click come when the sound finnaly comes or does it come immediately after the first click? The reason I ask is that the second click you hear in a receiver is actaully sending the power from the transformer to the amp stage circuitry. The fist click is just powering on the unit itself. -audioman00

 

[jabch]

realys are clicking

Thanks for the reply audioman!
I just tested this:
- push standby - hear click
- one second later - another click
- 4-5 seconds later - another click - no sound
the first click sounds like multiple contacts closing at the same time, whereas the following two are cleaner, i.e. sounds like one contact closing.
Does it make more sense?

Thanks

 

[jabch]

...18 minutes later

follow-on to my previous reply:
the sound finally came on after 18 minutes - no clicking of relays however when the sound came on

Thanks

 

[audioman00]

Ok it is really starting to sound like a weak power transformer, the third click should not take any more than 1 sec max. after the second. The power supply is taking too much time to get the correct voltage reading to the control IC chip which in turns is confusing the unit into thinking it has been overloaded and resets after several minutes. Try one more thing for me if you will: Disconnect all spkrs and see if the same thing happens. If not you may have a larger resistance or "ohm load" in 1 or more spkrs that is overloading the unit. If this fixes the delay, hook up only the two main L and R spkrs and try again, the receiver might have a bad amp section in the surround region only.

 

[jabch]

more data

I omitted to mention in my earlier notes that when switching from one source to another (e.*. CD to DVD to FM) each time there is a similar delay until the sound comes through, in the order of several minutes.

This morning I was going to test audioman's suggestion to disconnect the speakers to see what the delay was for the relays to kick in. Again, with the speakers connected it took about 14 minutes for the sound to come on after pressing the standby switch with the DVD source turned on.

So I started to experiment. To my amazement, the thing worked perfectly, without doing anything to the speakers!! I could switch from source to source without delay, I could turn the receiver off for a minute, turn it back on, and it worked as it should (I could not turn it off and on before without another delay). The beahvior of the relays in this condition was as I described in my earlier posting - it took a few seconds for the third click, at which point the sound came on. ...however, this only lasted for about 10 mintues - now I'm back with the delays!

Frustrating!

I also disconnected the speakers to see if there was a difference in the relays closing as audioman suggested - no difference.

What next?

Thanks for any (encouraging) thoughts

 

[audioman00]

encouraging?

Well, only if you consider finding your nearest onkyo repair shop encouraging. Wish I could help you further, but the onk is in dire need of service work. Sorry wish it was a simple fix.