The actual opto is through hole but the rest of the components are not.
As this is the second opto board fault mentioned in this thread I am assuming that this opto board has only been made for AC/DC and either they have a bad batch of transistors or some one stuffed up and specified a transistor that is not right for this application. 

Time will tell.

And they must have a really crappy batch of #89 flash lamps. I had to replace 6 of them because they were blown.
At least they were all easy to get to.

Don't get me wrong, I am not knocking Stern, we don't live in a perfect world.