Does anyone know how to get the magic

that's a buffer, I think, with tri-state outputs. It's an obvious thing to blow and probably nothing else it is damaged. Did you short an output or something?

First, rotate the picture! Then purchase a replacement on Digikey. That is the McMaster of the electronics world. Mouser is also good. The chip is a 74125 chip. SN means Texas Instruments, I think, and the ACHT is sort of a speed and current rating. So get the same chip if you can. Digikey is a bit industrial but you'll be able to find it. Check the package before you buy. You might consider buying a DIP socket, if this problem is likely to happen again.

I recommend this de-soldering tool. Add a little solder to the joint and suck it before the flux is used up. www.amazon.com/gp/product/B0932TJX9X After you can see the solder is removed from each pin, you're allowed a tiny amount of prying. If you come in too hot, you might pull a trace off the board, which makes everything harder.
 
Nice catch; that little black blemish on pin #11 is smoke residue, as is the odor.
It's supposed to only handle logic level signals, wonder what caused the heat?
 
Pin 11 is an output. Could be a shorted output or over-voltage on the whole chip? Not sure. Just replace the chip.

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durableoreo said:
Pin 11 is an output. Could be a shorted output or over-voltage on the whole chip? Not sure. Just replace the chip.

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If Vcc was applied to GND, and GND was applied to the VCC pin the part is toast. Just replace the part, but this time in the correct orientation. Hey, it happens to all of us. The part shouldn't be expensive. Since the part is NFG, just cut the pins off then individually pull the pins when the solder is melted, one by one. It's way faster than trying to free up all the pins, and causes less damage. Then remove all the solder, repopulate and resolder. Shouldn't take longer than a couple minutes.
 
I'm tossing the entire board. I have 199 more of them.
I also have 199 more of the IC's

I know what I did wrong. It will work fine if I just put the IC on the opposite side of the board. I already soldered up a new one and it didn't sound like Rice Krispies when I plugged it in and, oddly, no special smoke came out. Should be good to go.
In my haste, though, I put my output screw terminals on backwards so I need to redo those before I can test it fully.

Today I discovered I have a few IC sockets for this size. I don't really need them as the board design is toast if it doesn't work. I can't do anything about it in that case and have to go back to the breadboard to find out where I went wrong.

This is all just a theory coming to test phase so it's not a huge loss. The most I will be out is the cost of the boards.
 
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