Axiom Home Page Forums General Discussion Technical Questions "Protect Mode" - H/K AVR-235

This past weekend I turned on my trusty H/K AVR-235 to listen to a DVD (Gov't Mule - The Deepest End) and to my shock and horror my reciever went into "Protect" mode. After doing some initial analysis I discovered that it only went into protect mode when my surround speakers were engaged. I could listen to 2-channel + sub just fine.

For my surrounds I use the Bose mini-cubes through the bass(less) module. this is a temporary setup until I get some QS8's!! The rest of my system are M60Ti mains and a SVS PB10 sub.
Does anyone have any knowledge as to what would cause the reciever to go into "Protect" mode? I haven't finished my analysis yet but i'm hoping to prove that there is an issue with my Bose and not my HK. Any comments (other then Bose bashing are appreciated). Thanks!!

This is usually the type of thing caused by a stray wire or two shorting things out at the connection point. If this is temporary as you say, have you wired some speakers (like the Bose surrounds) into the HK recently?

If so (and even if not) check your connections very closely. It's likely that you have the stray wire thing going on. You might even want to re-do the connections entirely, just ot be sure.

You may be dead on with the stray wire. We had company the night before and I know my wife was shifting some things around. I have another reciever that I don't use very often that I may try the Bose on just to make sure. Then I'll reconnect them to the H/K. I really like my H/K ,although, I have read others having issues with its protect mode. I really hope its not a reciever malfunction. If it should happen to be that the Bose themselves are dead and I can prove that it was my lovely wife that may have causes the incident then maybe a pair of QS8's are in my near future : )

RD, as Ray pointed out, the most common cause is a loose strand of speaker wire causing a short, so even if they look okay carefully reconnect them to the surrounds. A second possibility is that an internal short has developed in a surround speaker, possibly from vibration. A receiver problem is a third possibility. If reconnecting the wires doesn't correct the situation, connect your main speakers temporarily as surrounds. If there's no problem it would indicate that a Bose surround is the cause; if there's still a shut-down, the receiver would be the suspect.

I agree with the above. Some more tests are warranted. I sure hope that it is just a stray wire or something simple like that.

Please keep us informed.

JohnK, very good suggestion...thank you. I'm hoping to perform the additional tests this evening. I'll let you know.

Thanks again

Hi rdwarn,

Another possibility is that you are running the H/K's speaker-level outputs for your surrounds into that Bose bass module. If memory serves, Bose puts all its amplifiers into the bass module. So, you'd be connecting speaker-level outputs into inputs intended to receive a low-level (a few volts) signal.

I suspect the H/K protection circuitry is triggered by the strange impedance it senses when you connect the surrounds to the Bose low-level inputs.

Regards,

I had a set of those cubes for a while. Damn things smoked two receivers on me. Granted, they were both left overs from HTIB systems, but I believe Bose speakers have unique impedance. I never did check into this as I sold them pretty quickly. I do know all their vehicle speakers/amps are unusually low and are not interchangeable with aftermarket amps.