Yamaha HTR2067 repair help required please.

[SteveC]

Hi,

I have an HTR2067 that appears to have a blown subwoofer channel.  I found the subwoofer connectors disconnected, not sure how long they were like that.  Also not sure if they ever got shorted.  I suspect when my wife moved some furniture that was when the wires got disconnected.

Does this model have output protection of some sort?  Anyone konw where I can get a service manual?  I am a qualified tech.

Regards,

Steve

[mzacharias]

There's no protection circuit for the subwoofer pre-amp level output, and no need for any. Most likely a broken solder pad or damaged eyelet at the jack itself, or disabled in the setup software. (There would be one or more muting transistors involved, as with all channels in a modern receiver.)

[SteveC]

Thanks,

I'm not using a powered subwoofer, the s/w speaker is connected to the o/p jacks on the rear of the unit.  I haven't tested the cable yet as I only discovered the fault late yesterday.  I plan to swap the s/w o/p with one of the surround o/p to see if it definitely the s/w channel after I test the cables.

In my early days as a tech (I am now retired) I was taught not to leave speakers disconnected as that would blow the o/p chips, hence my thinking that as the leads had become disconnected, the o/p stage might have blown.  Modern gear might be more robust though.

Regards

Steve

[SteveC]

An update.

Not sure what happened, after entering diagnostic mode and testing all channels, it came good.  Maybe yesterday for some reason my ears weren't hearing the bass as I was recovering from a bad cold.

Strange.

Regards

Steve

[mzacharias]

Thanks,

(snip)

In my early days as a tech (I am now retired) I was taught not to leave speakers left disconnected as that would blow the o/p chips, hence my thinking that as the leads had become disconnected, the o/p stage might have blown.  Modern gear might be more robust though.

Regards

Steve

Solid state amps don't care about an open speaker load, but obviously speakers wires left unconnected at the free end is asking for trouble, shorting out especially.