What is this chip?
Based on context, I'm guessing some kind of NAND gate/buffer.

Pin-1 is hardwired to Pin-7.
Pin-2 is grounded.
Pin-3 is the output where the processed input from Pin-1 exits the chip.
Pin-4 is GND.
Pin-5 is the input of interest.
Pin-6 appears to be another input of interest.
Pin-7 is hardwired to Pin-1.
Pin-8 is +5V.

So, wired like this. The input signals are 3.3V logic, and the chip outputs 5V logic.

I'm guessing at something like a Dual 2-input NAND gate, with open-drain outputs: https://assets.nexperia.com/documents/data-sheet/74LVC2G38.pdf

Just need to identify the exact part.

I don't have an answer for you but I love how this is the EmpegBBS version of https://www.reddit.com/r/whatisthisthing/

HD74LV2GT125AUS dual bus-buffer with 3-state output, or compatible?

https://www.renesas.com/us/en/document/dst/hd74lv2gt125a-rej03d0148-0200z?language=en&r=527771

Found via https://smd.yooneed.one/

Peter

The HD74LV2GT125AUS doesn't match the pin-out unfortunately, but a 74LVC2G38 does match and is probably the part.

As it turns out, the failure was in another chip just upstream of of it. A teensy tiny 8-pin + GND chip about the size of a grain of sand. Turned out to be a 4ch ESD protection device, which makes sense -- it failed and protected the rest!

Thanks all!

The mystery chip above has been identified at last: 74HCT2G125DP which is a 2-gate version of the 74HCT125.