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I would be very suspicious and check the rails etc. It should be pretty hard to kill an OPA1678 with some R on input and output. ESD is a possibility but I’d be surprised if there’s no protection diodes in these DSPs.
 

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It's your own fault from very bad practice.
NEVER EVER hot plug RCA leads , that would be the quickest way to blow your speakers if there isn't a good connection straight away (floating input) , friend of mine blew some expensive pro pa tweeters setting up for a big function doing exactly as you did , whenever you disconnect or connect anything electrical ALWAYS ALWAYS disconnect the power first or at least make sure it's powered off , you are just asking for trouble and have just been lucky so far.

If you were in Australia I could have fixed that for you , very easy to replace the ic with a hot air rework station like I have at work and I deal with surface mount components ( 0402 and smaller ) all the time as I'm an electronics tech.
Quality gear, especially designed for automotive, should have protection/clamping and/or AC coupling.

Thanks for the heads up, I've honestly never heard of this advice and wish I saw it sooner, I very often use to do that without consequence, guess it's a lesson learned
It really shouldn't be a problem.
 

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Sorry that's just wrong and bad practise and bad advice , like I said NEVER EVER hot plug anything doesn't matter if it's the most expensive piece of equipment in the world you should NEVER EVER do it , again it's very bad practise and just asking for trouble.
I'm an EE with 20 years of experience. If hot-plugging line level connections kills something, it was designed by morons.
 

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How you know it is OP amp and why you think it is? It can be RTC or many more things.
The fried component is an OPA1678 and a resistor array.

ESD damage usually isn't severe enough to induce smoking - the chip usually just stops working right.
Usually not by itself, but it’s theoretically possible it can create a short to a rail in the chip and that could result in what’s seen here. Also unlikely to be ESD with series resistance and coupling caps. I’d have to draw out the schematic to see which resistors in what positions smoked, but you don’t smoke those resistors without a lot of current through them. The op-amp can’t source that normally and is short circuit and thermally protected.

Some kind of transient or overvoltage most likely killed this. I’d definitely look at what was plugged into it. Unfortunately, line outputs on a lot of gear aren’t protected with clamps it seems.
 

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It definetly not OPA 1678 because there is no O nor A; actualy its not clearly seen which letters are in front of numbers nor manufacturer. Resistor array, numbers on IC and taking in account its only one (OP amp should be atleast one per chanel); my first guess would be RTC.

But its just a guess....
It’s completely obviously an op-amp in SOIC package. It’s got TI markings and font. I’d bet $10k it’s an OPA1678. I buy 1000s of these per year (various models). I think I know what I’m looking at. It’s a dual. It’s not a freakin RTC lol, you’re nuts. The resistors are input / feedback / output networks.

Blue Font Circuit component Electric blue Electronic device
 

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So for giggles I started up the amps today, jumped the remote on to constant 12v and they turned on, along with a little turn on pop so makes me think amps are def causing that

I probed the inside of the RCA and the outside the barrel on all the RCA inputs, I did get a few readings of ~5mV on the A and B channels but it wasn't consistent, nothing on the C and D channels

However on the sub amp, when reading between positive and negative across both the same RCA and the opposite (Pos of ch A and Neg of Ch B for example) I would get readings like this, the highest one I measured was about 60-70mV but could sonsitently get around 10-20mV

I'm not sure how electrically significant that is, my understanding is that amps usually look for 4v input, so .01V-.07V being less than 2% of what they would normally operate at doesn't sound like a lot, but it is also going the opposite way
A few mV of DC offset should be nothing to worry about. Turn on transients are not uncommon either.
 
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