Opto-couple Die burnt possible cause

[Soddy]

I am facing on Detector (output) side Die was burnt after application on Switching power supply as below Picture, actually, this Detector Die side were able to resist 130V / 1500mA, the voltage was limit as 12.8V by Zener Diode inside of IC and current is not much from this IC supply,

What are possible cause of Spike or high current/voltage are made the Detector Die burnt? anyone are found this issue or
please suggest, thanks.

 

[73's de Edd]

Sir Soddy . . . . . Sa-wat-dee kraup

Measure from pin 1 to 7/8 of your STR and see if your internal power FET inside hasn't shorted.
Also check on its side effect on R228.

73's de Edd

 

[Soddy]

Sir Soddy . . . . . Sa-wat-dee kraup

Measure from pin 1 to 7/8 of your STR and see if your internal power FET inside hasn't shorted.
Also check on its side effect on R228.

73's de Edd

Dear Sir 73's de Edd,
Sa-wat-dee-krap,
Thank you so much for your suggested, so, mean that some leakage current/voltage are come from
STR IC? but, after replace Opto-couple product by one, the circuit are continue work, it is quite headache for me to find the real root cause, let I check and if it is short as your suggest will replace by new IC, thanks.

 

[Soddy]

Dear Sir 73's de Edd,
Sa-wat-dee-krap,
Already checked the STR , it is leakage, but, R228 are not failed, it is normal working. thank you so much for your very good suggested,