We have had several display boards on our PB 840's fail. Is anyone else having this problem?

KHRT,
We have one 840 at our school and we have had its screen fail as well. The rep was nice and has since fixed it, but it did fail with minimal use at our school.

KHRT and Light7324

Why did the display boards fail? Was there an error code as well?
Please let me know since one of our sites is set on purchasing a couple more 840s.
Thanks

Unsure why boards fail, repair tech unable to trace problem and as vents were under warrenty they just replaced boards. And yes we did get warning alarms associated with the boards failure, but we have also a large number of oxygen sensor failures too.