Monitoring board

The main failure mode is flash memory failure. The flash space runs out, or the flash develops bad sectors or bad blocks.

<!-- review notes

• sentence 1: support check: partial - Passages list insufficient flash space and bad sectors/blocks as causes of the Flash Fault alarm, but don't say this is the 'main failure mode' (a framing/qualifier not stated).
• sentence 1: review: partial - The passages give insufficient flash space and bad sectors or blocks as causes of the flash or monitoring-unit fault, but they never call this the 'main' failure mode. -->