I'm blanking on the exact models I used; I'm fairly certain they were tds700s or tds71xx, but a lab I ran had about a dozen units and we had nothing "fry" in the 4 years I worked there. What applications would result in these catastrophic failures?

i thought maybe it was just something regionally here or the way people stored em, but i was in a position to refab many a few years ago and totally agree. tek had 100% repart rate and seemed like anything else (brand wise) was always in better condition internally even when way older.