Sony STR-DG910 shut off "Protect"

[Shifter125]

I recently replaced my Onkyo TXDS656 w/ a new Sony STR-DG910. The reason I replaced the Onkyo was because the sound would shut off and flash 'protect' at mild volumes during certain movie scenes such as explosions or FM radio at medium/high levels. I thought it was old and didn't have enough power.

Well, now that I have the new Sony, I have the same problem. The Sony manual says it's when there's irregular current output from the speakers. The auto calibration menu tells me that the right front and right surround speakers are out of phase. I've switched the terminals and that caused all speakers to go out of phase so I switched them back. I've completely re-wired all speakers with new monster cable / connectors.

Speakers: Center: Polk CS245 / Sub: Polk PSW200 / Surround: Polk RC85i (4-Ceiling mounted)

I'm completely perplexed.

Any insight would be appreciated, thanks in advance.

 

[Haoleb]

Do you have enough ventilation for the reciever? It could be its getting too hot and going into thermal shutdown.

Also it could be one of your speakers is causing the reciever to do this. You said you recently replaced all your cables, But double check all your connections to make sure there are no stray strands of wire touching.

If this is constantly happening try hooking up just one speaker at a time and see if you can replicate it.

 

[mtrycrafts]

I recently replaced my Onkyo TXDS656 w/ a new Sony STR-DG910. The reason I replaced the Onkyo was because the sound would shut off and flash 'protect' at mild volumes during certain movie scenes such as explosions or FM radio at medium/high levels. I thought it was old and didn't have enough power.

Well, now that I have the new Sony, I have the same problem. The Sony manual says it's when there's irregular current output from the speakers. The auto calibration menu tells me that the right front and right surround speakers are out of phase. I've switched the terminals and that caused all speakers to go out of phase so I switched them back. I've completely re-wired all speakers with new monster cable / connectors.

Speakers: Center: Polk CS245 / Sub: Polk PSW200 / Surround: Polk RC85i (4-Ceiling mounted)

I'm completely perplexed.

Any insight would be appreciated, thanks in advance.

Or, if you have an ohm meter, check the wires.
But, it most likely is the ventilation.

 

[Shifter125]

Thanks for the reply...the receiver is wide open, plenty of air, the player shuts off right away at medium volume at the same spot of a given scene. For instance, I'm using Top Gun to test and at the beginning of the movie when the jets take off...'click' "Protect" flashes and shuts off. I put in a couple other movies and the same thing happens when intense sound is a part of the scene.

What am I looking for with an ohm meter?

 

[mtrycrafts]

Thanks for the reply...the receiver is wide open, plenty of air, the player shuts off right away at medium volume at the same spot of a given scene. For instance, I'm using Top Gun to test and at the beginning of the movie when the jets take off...'click' "Protect" flashes and shuts off. I put in a couple other movies and the same thing happens when intense sound is a part of the scene.

What am I looking for with an ohm meter?

You would check to see if any of the speakers have a low DC resistance. Measure from the leads at the amp end. That would/could also show wire issues. It may take a bit of troubleshooting but at the volume you indicate, it shouldn't happen.

By the way, do you have a sub? How are the speakers programmed in the receiver, small or large?

 

[MDS]

If there are no stray wires causing a short and the receiver has plenty of ventilation I'd be inclined to say that it is the speakers themselves. Are they very low impedance or perhaps defective due to age that causes a super low impedance swing? A very low impedance will shut off just about any reciever.

Are you running A+B speaker terminals at the same time? That would do it too.

 

[Shifter125]

Thanks again.

The sub is Polk PSW200, speakers are programmed large, but I've tried small with no change. I just have A speakers running, nothing on B.

I'll go to Lowes today and pick up an ohm meter...thanks guys.

 

[mtrycrafts]

Thanks again.

The sub is Polk PSW200, speakers are programmed large, but I've tried small with no change. I just have A speakers running, nothing on B.

I'll go to Lowes today and pick up an ohm meter...thanks guys.

I just checked your speakers again; you have 4 ceiling mounted speakers. Are they all for the rear? If so, how are they connected? one to an am channel?
What about front speakers?

 

[mtrycrafts]

If there are no stray wires causing a short and the receiver has plenty of ventilation I'd be inclined to say that it is the speakers themselves. Are they very low impedance or perhaps defective due to age that causes a super low impedance swing? A very low impedance will shut off just about any reciever.

Are you running A+B speaker terminals at the same time? That would do it too.

The speakers he listed are ok, but I just saw 4 ceiling surround. No front listed, so I asked. Possibly he has speakers in parallel on the back?

 

[Shifter125]

The two front ceiling mount speakers are connected to the front A posts and the two rear ceiling mount speakers are connected to the surround back posts.

I bought an ohm meter at Lowes...here's what I found:

RF: 8.1ohm
LF: 8.1ohm
RR: 8.1ohm
LR: 3.96ohm
Center: 1.0ohm

I've ordered a new center and new rear speaker...great advice, thanks all.

 

[mtrycrafts]

The two front ceiling mount speakers are connected to the front A posts and the two rear ceiling mount speakers are connected to the surround back posts.

I bought an ohm meter at Lowes...here's what I found:

RF: 8.1ohm
LF: 8.1ohm
RR: 8.1ohm
LR: 3.96ohm
Center: 1.0ohm

I've ordered a new center and new rear speaker...great advice, thanks all.

There you go. I hope you ordered the same one you use in th efron't left/right one for a better match.

But, the question still remains then. Is it a short in the wire or the speaker itself?

 

[Shifter125]

I replaced the orginal wire / connectors first and the problem remained. I have brand new wiring / connectors with the readings noted above so I think it's the speaker. I did order the same RC85i to replace the bad ceiling speaker, but I upgraded the center to a CSi3.

 

[Muckrak3r]

I have the exact same receiver, the dg910, with the exact same problem.

I have been fine for years, but a couple days ago bought 2 Polk Monitor 50's for the 2 front speakers. If I tried to do the auto calibration the receiver would go in to 'Protect' mode. If I turned up Halo ODST to a slightly loud level it would go into 'Protect' mode, same result for movies.

I tested my wiring with an ohm meter tonight. With my original Infinity bookshelf speakers I got these results:

FL 6.8
FR 6.7

I then put the new Polk Monitor 50's in there and got these results:

FL: 4.1
FR: 4.0

Why is there such a huge drop between my old speakers and the 2 new ones? I used the exact same speaker wires (existing) and got nearly a 3 ohm drop????

I have yet to replace the speaker wires with new 14 gauge wire, but I seriously doubt when I do it will jump up the ohms on the Monitor 50's.

Anyone have any suggestions, advice?

 

[markw]

OP, you may want to check for shorts in the wiring by disconnecting the questionable speakers from the wires and then disconnect the wires from the receiver leaving the wire attached to nothing on either end. When you do a continuity teas on the + and - speaker wire leade, it should read infinity. If not, then it's a wire problem and the speakers may be fine.