# Denon 789 Protection Mode



## MatrixDweller (Jul 24, 2007)

I'm trying to help a friend set up his system. Unfortunately I have to do it over the phone since he lives 300km away. The problem he's having is that his Denon 789 shuts off after 10-30 minutes of use.

He's not very technically inclined so it's hard to diagnose from his description of what's happening. He says that last night it shut off, with a popping sound, after about 30 minutes when he got up off the couch. He swears it's because he put pressure on the floor in front of it. He said another time it might have been caused by his kids jumping around.

He has the AVR in an entertainment unit and there is a shelf about 3" above it. The back of the unit is sealed up too. My inclination is that it's over heating, but he says that it's not too warm to the touch. He has been listening at moderate levels, say around -25dB.

He only has two speakers hooked up to it currently. Two Klipsch RF-62's. They are 8 ohm compatible, but I've heard they can dip fairly low in inpedance. I've only used higher end Denon receivers, but figure the 789 should be able to drive the RF-62's without issue, even to fairly loud levels.

The other components in his system are a Sony BD550 Bluray player and a Scientific Atlanta 4300 HD cable box. He has only been using the cable box and that is what triggered the protection mode shut off.

I've asked him to bring the AVR out of the cubby hole that it's in and make sure there is plenty of space around it and nothing above it. I said that I could make him a cooling system for the back of his entertainment unit or suggested he could use a product like one of these so that it will pass the WAF. He's convinced that it's defective though and wants to bring it back to Future Shop for an exchange.

Any ideas/opinions?


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## brucek (Apr 11, 2006)

It could be a couple of stray fine wires from a speaker cable shorting at the receiver or speaker that is exacerbated when someone jumps around.

As you suggest, he has to test the heat theory by running it out of the shelving unit.

brucek


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## MatrixDweller (Jul 24, 2007)

I went over that with him and he rewired the speakers. He made sure all the wires were twisted with no frayed ends. 

Could a speaker actually be faulty?


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## salvasol (Oct 31, 2006)

:duh: Brucek beat me with my suggestion ....



MatrixDweller said:


> Could a speaker actually be faulty?


Could be, Did he had the same problem before???? or are they new set up in the system???

What about the power cords???...I have an outlet that is really loose, when you move the cord just a little it will power off; ask him to be sure that the cord is secured on the outlet :yes:.


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## MatrixDweller (Jul 24, 2007)

I made a point of telling him to check all the connections, speaker, HDMI, power, etc. He has everything hooked into a power bar, and the only device that powers off is the AVR. 

Of course it's really hard to diagnose everthing and be sure they are doing everything exactly as you tell them when you're doing it over the phone. 

Everything in his system is brand new, even all of the cables. He and his wife got everything as a package at Future Shop. So far I've spend about 2 hours helping him set it up. The Denon 789 manual is pretty useless for someone who knows diddly. Of course I'm the type that just needs to feel around the menus to set things up (can't really do that over the phone though).

I was wondering what elese could be the problem, and the tip on a speaker having a loose internal connection was a good tip. I should have though of that. I'll be sure to update this thread when I know more or find a solution.


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