HELP HELP HELP - Just blew my amp, can't afford a new one.

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Hi Guys, my only amp currently is a Denon AVC A11SR.

I just accidentally shorted the output of one channel somehow whilst swapping speakers (rather stupidly i did this live)

Anyway, whilst pulling the speaker cable out of the red output terminal the cable came into contact with the amplifier housing, accompanied by a loud bang and spark, then a chemical smell.


I'm about to open it in search for burnt component(s). The amplifier turns on but when the power stage relays kick in it goes straight back into protective mode, which I hope means the protection kicked in fast enough to confine damage to the power output.

Don't really know where to start other than open it up and take a look, any and all advice is gratefully received.
 
HS? I should say I've got it open now, no sign of where the damage is despite the smell which is somewhat irritating - can't see any damage, it's clear which amp channel is potentially shorted but not clear if there's damage on that board or at the PSU stage :(
 
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You egg.

Check voltages at emitters of output devices or Emitter resistors, or inductors...

I’d definitely track it back from the effected channel output...

MN/P 1715 are based on SanKen MT200 devices... (takes something stupid to kill one)

I haven’t heard antone yet come back on hFE of them, there are non ******** options (seen what Denon charge?!)

The SM is on Hifi engine, use that to check locate output voltage on relevant channel

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What speaker output was shorted...I’ll try n speed up exactly where to check

Shorted speaker output was Front L

I should say that though i have basic electronics skills I'm no electronic engineer, i design speakers not amplifiers!

All I can tell you so far is that there's still a voltage output to the amplifier boards from the PSU so at least the PSU isn't blown - i think everything points to the front left channel being blown somehow, though I will check fuses now

(no blown fuses)
 
Seems there is a fast checkpoint available on each channel.... these all should be 0V or close to with reference to ground...
 

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I use 6, (main monitors tri amp'd)

But the amp has 7.... so I can get away with losing one. Not ideal but if it's a quick fix it seems like the best solution

There's no voltage on any of the test sites but I wouldn't really expect there to be given that they're set to 0 at factory anyway and there's no way of getting voltage to the amps at the moment.
 
If there was a short or massive dc imbalance, you would see up to 60V at either side to Test point to ground...

Hold - meter Lear to metal base of amp... check on each side of TP - should be 0v

This often triggers protect not to kick in

—-

If there is no dc voltage present, there could be another issue
 
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