MP2352 - Main power light dead - all else well.

[Polarbear]

I have a strange one in the workshop.

The machine will power up and work as per normal, with one twist - the main power light stays dead.

I have replaced the board on which the led resides, as well as the lcd driver board that daisy-chains onto that board, but no change.

I have checked the loom - no visible pinches or breaks.

Has anyone seen this before?