Like the title says. This Sundown SAZ-2500D was in protect mode. Removed output FET's and checked them, all tested good. Power supply also seemed to be ok. Tried to power up amp again (through a current limiter) with no outputs installed and it was still in protect. Removed driver transistors and tried to power up again and it was still in protect.
So I bypassed the protect and powered up again, still through a current limiter. The amp powers up, but is showing (-)Rail voltage on the + speaker outputs when referenced to the (-) speaker outputs. Again this is with no output transistors installed.
I checked, double checked, and triple checked for solder bridges on the ouput transistor pads. There is none.
So I bypassed the protect and powered up again, still through a current limiter. The amp powers up, but is showing (-)Rail voltage on the + speaker outputs when referenced to the (-) speaker outputs. Again this is with no output transistors installed.
I checked, double checked, and triple checked for solder bridges on the ouput transistor pads. There is none.
Since there's an unknown fault, anything's possible but shorting the positive speaker terminal to to the negative speaker terminal shouldn't affect the primary to secondary ground. I'm not familiar with this particular amp but the connection between the primary and secondary is generally near the power supply driver circuit.
Hi Perry,
I'm not familiar with this amp either, and you are right about the normal place for this resistor. I have serviced a good number where that resistor was near the input RCA jacks though. Only the first stage of audio was floating and the rest of the amplifier was tied to the car ground directly.
You are also correct about the effects of shorting the output of the channel. That might not have anything to do with the puff of smoke, but if the driven terminal touched the RCA ground for the briefest moment, this could happen.
Hi Troy,
Do you have a schematic for this amplifier? A close-up photo of the damaged area, and of the entire amp might help us as well. Also, a picture of your connections on your bench please.
-Chris
I'm not familiar with this amp either, and you are right about the normal place for this resistor. I have serviced a good number where that resistor was near the input RCA jacks though. Only the first stage of audio was floating and the rest of the amplifier was tied to the car ground directly.
You are also correct about the effects of shorting the output of the channel. That might not have anything to do with the puff of smoke, but if the driven terminal touched the RCA ground for the briefest moment, this could happen.
Hi Troy,
Do you have a schematic for this amplifier? A close-up photo of the damaged area, and of the entire amp might help us as well. Also, a picture of your connections on your bench please.
-Chris
That was probably an op amp. I see the manufacturer impedes service by taking the numbers off the parts.
My guess is that they only sell these modules and not the parts on them. At this point you should let the manufacturer service it, or buy a different make. I would advise against buying any more of their products. If it were my amp, I would maybe get that one fixed, for sure I would sell any others I have and go for something that can be serviced. Removing part numbers is a childish game played by those with massive egos. Don't play their game.
Sorry, Chris
My guess is that they only sell these modules and not the parts on them. At this point you should let the manufacturer service it, or buy a different make. I would advise against buying any more of their products. If it were my amp, I would maybe get that one fixed, for sure I would sell any others I have and go for something that can be serviced. Removing part numbers is a childish game played by those with massive egos. Don't play their game.
Sorry, Chris
I know I had an issue with the IRS version of the 21844S in the NS-1's I was repairing. Tried 6-7 times and could not get a single one to work correctly without blowing outputs. As soon as I switched to the IR version, I have successfully repaired 15 of them without a single issue.
Only one way to tell, Ill put it in and see what it does I guess.
Only one way to tell, Ill put it in and see what it does I guess.
Hi Troy,
Really. My, how things have changed. It's almost like we are back in the early 80's when everything was a secret. They went one better back then and would use "house numbers" printed on ICs and transistors. We went through that in the mid-70's and up to the very early 80's. Adcom still pulled that ... stuff.
Hi Perry,
Thank goodness you are here and familiar with the industry these days. You too Troy. If you can service these efficiently, of course you can, and should continue servicing this product.
I'm one of those guys that would repair the module. Remember went Fosgate did that module thing? That was a pain.
-Chris
Really. My, how things have changed. It's almost like we are back in the early 80's when everything was a secret. They went one better back then and would use "house numbers" printed on ICs and transistors. We went through that in the mid-70's and up to the very early 80's. Adcom still pulled that ... stuff.
Hi Perry,
Thank goodness you are here and familiar with the industry these days. You too Troy. If you can service these efficiently, of course you can, and should continue servicing this product.
I'm one of those guys that would repair the module. Remember went Fosgate did that module thing? That was a pain.
-Chris
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