After about 1000 units all of a sudden two units used by the same customer have failed.
The diodes are a full short (FMKA140), understanding of a breakdown under high reverse voltage was that it's non destructive and them the diode will recover so long as it isn't damaged by heat. There is no sign of heat damage.
Has anyone ever seen a breakdown like this? Any ideas what would cause it?
Thanks for any help
Ralph