Out of curiosity, and because I figured that it couldn't do any more harm, I sprayed some contact cleaner into the affected socket, and then blasted it with compressed air. The chip at LS154 still overheats, but the area of the board immediately to the left no longer does (I know I said to the right in my previous post, but I'm dyslexic. Sorry). How the chip overheats also has changed, as before the heat was concentrated to the middle and upper left of the chip. Now the chip only overheats in the upper right (yes I wrote that right, it's the right) corner of the chip. The heat is also more concentrated in that area, and it takes almost twice as long before I can feel it. There is, however, no corresponding change on the screen, and no beep on power.
I'm pretty sure now that the overheating issue is a short somewhere in the socket, otherwise, why would the contact cleaner have changed where the chip was overheating? I'm guessing the same is true for the screen issue and the failure to boot, however, I'm not sure where that short might be?
Also, the MC1741CP chip that was lost in extraction? The replacement was generic, marked simply 741, and I'm curious now if that was truly the right part?
Note: I'm orienting my board as it would be in the //e, RAM to the front and expansion slots in the back, just so I'm clear as to what right and left are.
Also, I think Osgeld was right, an alcohol bath would probably have been more efficient, and caused me less followup. I just didn't have enough alcohol or anything to submerge it in. I was being impatient, and I'm paying the price.
Edited by DistantStar001, Tue Sep 4, 2018 5:59 PM.