Yeah, but I was sure to wire it right… since they’re in a mirrored sort of configuration, the wires need to cross each other – the chip on the bottom right is the same as the chip on the upper left, and vice versa.

Wired it up like that, and guess what? No dice. Same ****. So, hesitantly, I tried plugging in one of the upper bulb’s wires. Same ****. Plugged both of the upper ones in and unplugged the lower ones (so the lower is now only powering the upper). Yes, same **** (it only powered the upper light for a second, then shut off). Plugged them both in and plugged the power in. It came on and stayed on until I unplugged it a couple seconds later. So yep, it was “working” (limping along) on that one remaining IC. Now I just need to replace them. *facepalm*