Pair of Monitor 30 speakers completely silent

kevinrontel

I have an alcoholic friend (and yes, that is relevant to my question), who recently asked me to help him fix his receiver because it wasn't making any sound. I was surprised to discover that the problem is NOT the receiver and NOT the speaker wire but it IS the speakers.

The speakers in question are Polk Monitor 30s. They make absolutely no sound...no hum, no rattle, nothing. I've tested them on two stereos.

I opened them up and found no busted wires and no obviously burned up components. Unless I'm blind, these things don't have fuses.

I suspect my friend was playing his stereo incredibly loud for a long time, burned up something in one speaker and failed to notice this due to an advanced state of booziness. He then probably turned the stereo up to compensate for the lower volume and fizzed the second speaker.

My questions are two:

1) Is this a plausible scenario?
2) Any suggestions on my next step in diagnosing the problem?

Thanks!

RuSsMaN

At a VERY conservative level on the volume knob, and with something like talk radio on, hook the midbass driver up directly to the known good source amp, if you get sound, the issue is not drivers, and probably crossover related.

cnh

RuSsMAN,

Knows more about this than I do. But I couldn't help noticing that this was your first post.

So Welcome to Club Polk-Kevin!

cnh

kevinrontel

Thanks, gentlemen. I wrote that last post in a hurry. Closer inspection (ie, with sufficient light), reveals that the ceramic resistors (5W5R7J, 5W1R8J) on both of the boards are burned to a crisp.

Just to be thorough, I took RuSsMaN's advice and connected the midbass drivers directly to the amp. No sound.

This seems to indicate that, in addition to the problems with the board, there's a problem with the drivers.

At this point, I suspect I'm looking at a greater expense and pain in the neck than my electronic skills (a weak 5 on a scale of 1-10) warrant, especially since I'm doing this as a favor.

Once again, thanks for you advice!

RuSsMaN

Sorry to hear, sounds like the speakers are completely toast, drivers and crossovers. The tweeters probably went first, and the midwoofers probably continued to play even though the voicecoils were fried due to them expanding with all the heat - then next was probably the crossover components, leading to complete failure (no sound). Once the voicecoils cooled, they probably warped and seized.

Cheers,
Russ