We made a 23w(50V/450mA) led driver following the report der256 and works good. But it is oberved that D5 (FR107) and C5(22uF electrolytic) heating up. D5 goes upto 70 deg and C5 go upto 64deg ! Kindly help u to solve the issue. Please note that we used LNK419 intead of 416 and not used any heat sink. Layout and all other component are same as der256.
Waiting for your guidance