Yamaha sw500

[g1]

It's possible that just the speaker is blown and the amp is ok. We suspected the amp because you said the speaker had shorted, which often will damage the amp.
Now you say the speaker was not shorted, so the amp may be fine.
There is a protection relay for the speaker, so if there is DC on the output the relay will probably do it's job and not engage. So we can't check for DC right at the output terminals with this amp.
It looks like if you put one probe on pin 2 of C206, and the other probe on pin 2 of C207, you can check for DC before the relay. I'm not sure if those connectors are installed though.

[ca7922303]

Appreciate your help. I'll try that when I get back in town later this week.

[ca7922303]

C206/207 both get 0-3.5 alternating on 200mv scale.

[ca7922303]

Correction: with one lead on c206, other on c207 pin#2s, reading 6.0 on 200mv scale.

[g1]

That's a good sign. Do you hear the relay click when you turn the amp on (may be a second or two delay)? Do you measure that same 6mV right at the terminals where the speaker will connect? If so, probably just the speaker got blown.

[ca7922303]

There is a click 1-2 seconds after power on. I can check 4 pin connector that I believe is to speaker.(don't have enclosure with me but do remember it was a 4 pin connector). I'll get back again shortly.

[ca7922303]

I previously gave readings on cn203(4 pin connector) of 8 & 10.6 mv depending on which pin black lead was connected to.

[ca7922303]

Correction: make that 8 & 14.6 mv on 200mv scale.

[ca7922303]

Connected known good speaker to both external outputs with same result, no output. I have been told that the clicking house that happens 1&2 seconds after power on is the amp going into protect mode and that the outputs are shorted. Any thoughts on that opinion?

[g1]

It's just somebody's opinion, you need to verify.
Check the output transistors for shorts. Usually it will be between collector and emitter legs. If you find a short, remove it from circuit and check again.
You don't want to just start replacing parts due to online recommendations. You can spend a lot of money and still have the fault.

[ca7922303]

Out of twelve(12) transistors, ten(10) show a reading other than OL on 200 ohm scale when testing emitter and collector and reversing leads also. Should I remove all ten(10) and test it test base to emitter and vase to collectir and give results first to possibly eliminate some if the ten(10)?

[g1]

Start by lifting just collectors (or emitters, doesn't matter which) and checking for low resistance between emitter and collector.

[ca7922303]

4-C3856 14Ps show OL with one leg removed from board on 200 resistance scale, 4-A1492 16Ps read OL on 200 resistance scale. 14Ps read 499 on 2000 resistance scale, OL with negative lead on emitter
16Ps read 532 on 2000 resistance scale with negative lead on emitter, OL with positive lead on emitter, 2-C4793s read 610 on 2000 resistance scale, 2-FMX22S read OL on all resistance ranges except 2000k when 1-reads OL with positive lead on emitter and OL down to 350 or less at a crawl, other FMX22S starts at OL and goes down to about 200 or less with leads on either way.

[ca7922303]

Got a 4 leg D10XB20 left in circuit reading OL on all resistance ranges.

[g1]

So no shorted outputs.

I have been told that the clicking house that happens 1&2 seconds after power on is the amp going into protect mode and that the outputs are shorted. Any thoughts on that opinion?

You didn't find any shorted outputs. And the relay clicking, I suspect, is the opposite of protect mode. I think it is the amp coming out of protect. And I think the test in post #34 & #38 confirmed that.
So possibly the 'no sound' issue is somewhere closer to the input and not power amp related. I could be wrong, but I don't have the unit in my hands so it is tough to say.

You would need to measure the voltage at the relay coil pins to see if you are in protect or not, after the click sound.