Soundstream Class A 10.0 problem

[kmarei]

Amp powers up
no fault light
it does get a little warm, but then again it's a class A so that's understandable
but i can't get any sound from it
measured the left and right outputs
both measure around 0.04-0.06v

outputs look clean


Power circuitry (looks likes it repaired?)


Resistor R156 is blown (below the 2 black capacitors)


ideas?

[kmarei]

notice the orange smiley sticker

[1moreamp]

Last two pictures near the bottom just left of center I see R156 is burnt completely up. I would start by replacing that component and looking around for other failed components. I lack any docs on this model so I can not tell you the value of R156. perhaps a closer area picture I could try and see what it does, and make a educated guess....


Looking around a bit I am inclined to think the burnt resistor is the ground connection resistor for the two different grounds and is likely a 10 ohm 1 watt resistor...hope this helps some...

[jeanious2011]

Some SoundStream amplifiers had revisions done to them. Thats why you see extra resistors by the transformer.

Those resistors are humping, lol. But my only concern would be why not replace them with a higher wattage resistor or value?

That R156 looks to me like a 1/2watt 10ohm resistor but not sure. Just judgin by the winds on it.

[Perry Babin]

Is the amp producing both positive and negative rail voltage (measure at the output transistors)?

Do you have positive and negative 15v on the power supply pins of the audio op-amps?

[azvrt]

Just out of curiosity, which revision is this ? Should be mentioned on the board somewhere ?
Don't worry about the orange sticker, it's on most boards.

[EBBCO]

I bet you will find one of your 2 or 3 position switches are at fault! 3 out of 10 I do have that issue.

[AKHeathen]

that appears to match my 1000s, even component name. if it is the same, then that resistor is tied between the common of the rails, and output rca shields, and all that entails. if you look in your top pic, you can see the 3 jumper traces between left and right output, just above the terminals. it's the center one, and jumps strait across to the left where you can see it feed the output rcas and continue under the row of resistors/caps. what exactly happened? another amp running of the output rcas?

[MOER]

This is NOT a class A amplifier. Have you any idea how large a 25w/ch 4 ohm pure class A amplifier would be?

The burnt resistor is the input output ground resistor, any value less than 47R is OK.

[hollbrow]

The resistor in that same area of my 700s is a 10 ohm/1W. Not saying thats definately it-
Just a comparison.