WE TRIED WITH DER337 WITH DIFFERENT WATTS 10W, 18W ,20W ALL ARE FLASHING
1. Can you provide us the output voltage and output current and L4 inductance of your design?
2. It will be a big help if you can provide us the drain current during this flashing condition. Auto-restart will occur in the following condtion:
a>FB not connected/ open loop
b>L4 is saturating
c>Sense resistor is too low.
d>C4 is shorted/ FB shorted
3. Send us also your schematic for review.