SM6T68CA part Failure

[erothdevices]

We have purchaed this 

SM6T68CA and since 10 years we have purchase but this time we got failure in the device. need to know what is the exact issue and why this is getting failed. 

is it dummy part

and if it is dummpy part then how could we identify. 

or 

is it batch issue. 

how would we identify the original and duplicate component if duplciate part through marking

[Douglas MILLER]

This post has been escalated to the ST Online Support Team for additional assistance.  Should anyone else have a similar question about device failures, please submit your request directly to the ST Online Support Team at https://my.st.com/ols.