On Wed, 14 Sep 2005 21:58:29 -0500, Martin H. Eastburn wrote:
Likely reverse voltage spikes from the supply. They can't take reverse voltage
at all.

Not in _my_ design, nope, couldn't be. Besides, the replacement
functioned for years, at least. So I still suspect the markings or,
possibly, the guy who fab'd the board but that's unlikely (ahem) maybe.