Automatic Litterbox Central

I've been a LM fan since the beginning, and although I've probably had 5+ die on me over the years, they have been well worth the money too me. I have three cats and four littermaids.

I had an LM700 die so I bought a few when I caught them available. Open the box, plug it in, nothing. Open the 2nd new one, dead. Third one, same. I'm trying different outlets, different power supplies, I made sure to clip the two zip-ties holding the rake. Nothing. The red light turns on, but the rake never moves. On one, it backs up a tiny bit then stops. Thee new units, all completely dead on arrival. So GD frustrating.

Any ideas on how to revive these? Or how to exchange for more new units?