As someone who has been in hardware development for many years, EVERY bitcoin ASIC vendor has mainly had issues with the Board design, and Thermals/Mechanicals.
Once the chip design is done, its real easy to call the Chip FAB up and ask for chips...
KNC - Ran out of VR modules because they bought an off the shelf part. Then had Capacitors catch fire probably due to not spec for enough ripple current.
Proof? KnC never ran out of VR modules. They even put more than needed on the first boards just to be sure nothing goes wrong. Yes they had some capacitors catch fire but i don't think it was for more than 20 customers which is ~5.5% out of 3600 Jupiters. But the units are stable as fuck. The other vendors hardware, even if they didn't had problems with components catching fire, they weren't so stable or they just died. So i'm waiting for proof for the statement that KnC ran out of VR modules otherwise it means that you are just talking out of your ass.