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[Bao Dinh]

Hi all.  I am new to this forum and will need lots of help from professionals like you guys.

Alright huge problem.  I was trying to install the new gain pots and channel 2 was not working at all. So instead of checking the solder points, I switch those 2 black wires that label 1 and 2 (thinking that would reverse the inputs).  I heard some noise and after that, the amp was doomed.  Every time I turn it on, the breaker would trip.  What would you suggest the problem(s) is/are?  Is there any way to test or fix the amp?  I was extremely stupid and that was the first time I had ever tried to fix something.  Thank you so much guys/gals.

[Scott Holtzman]

Hi all.  I am new to this forum and will need lots of help from professionals like you guys.

Alright huge problem.  I was trying to install the new gain pots and channel 2 was not working at all. So instead of checking the solder points, I switch those 2 black wires that label 1 and 2 (thinking that would reverse the inputs).  I heard some noise and after that, the amp was doomed.  Every time I turn it on, the breaker would trip.  What would you suggest the problem(s) is/are?  Is there any way to test or fix the amp?  I was extremely stupid and that was the first time I had ever tried to fix something.  Thank you so much guys/gals.

More bad news, since you pay attention to forum rules as much as you pay attention to wiring nobody can answer your question until you change your display name to your real verifiable name.


The good news is the amplifier is not worth much money so it was a very cheap learning lesson.  In order to become a professional you have to destroy much more expensive gear than this.


 

[John Roberts {JR}]

A common fault in power amps is shorted output devices.

JR

[Mike Caldwell]

Those were main power rail connections you swapped around not audio lines!

From the looks of the schematic you swapped the -55 volt with the power supply center tap.

[Jared Bartimus]

Those were main power rail connections you swapped around not audio lines!

From the looks of the schematic you swapped the -55 volt with the power supply center tap.

So they likely effectively sent +110V to components expecting +55V and +55V to components expecting -55V?  Assuming that is power supply output rails rather than the power supply inputs from the transformer.

[Russell Ault]

Those were main power rail connections you swapped around not audio lines!

From the looks of the schematic you swapped the -55 volt with the power supply center tap.

Under the circumstances, at some point, part of the advice given should be about line-voltage electrical safety (especially judging by the size of those capacitors). Killing the amp is one thing, killing yourself is another.

(I'm not the person to give the specifics of that advice; I just know enough to be wary...)

-Russ

[Mike Caldwell]

Under the circumstances, at some point, part of the advice given should be about line-voltage electrical safety (especially judging by the size of those capacitors). Killing the amp is one thing, killing yourself is another.

(I'm not the person to give the specifics of that advice; I just know enough to be wary...)

-Russ

Very True

" I was extremely stupid and that was the first time I had ever tried to fix something"

Poking around in something with high voltage, high current DC power supplies and line level voltage should not be a first DIY repair project.

You at least blew some of the output transistors and maybe even vaporized some circuit traces.
Did you smell anything and or hear a quick pop when you turned on the power......you did have the amp turned off and unplugged when you swapped those cables, didn't you?

[ProSoundWeb Community]