Hi All

I have a house full of philips led downlights, DN052B, and they are failing one after the other.  It's the usual LED failure with flickering and then going dim. It must be the driver.

So, I pulled the thing apart and checked the led bank, which seems fine, running at about 20V pulling 0.5A.  I de-soldered and tested the caps, N mosfet and diodes.  I can see some indication of heat on the yellow transformer but have no idea what it is as the printing returns no hits.  There is also the small current shunt double diode which appears oK too (looks like a small transistor at corner of board).  Any ideas?  What is the usual failure mode?