Diodes in SEG LED TV

[Nick]

The D11 on that board for sale does not look all that healthy either, yet they claim it is "PART HAS BEEN REMOVED FROM A WORKING ,DAMAGE SCREEN TV, PART IS TESTED AND IS IN FULLY WORKING ORDER."

Not sure it's a problem - all the photos of that board that I've seen have green gunk on D11, e.g.

https://spares2repair.co.uk/unknown-manu...4001011196

...and, for that matter, the OP's photos...

EDIT: Actually, it looks like there's a ferrite bead on each end of the diode, and the gel/glue is there to stop them rattling around and to keep them in place...