Hi all,
We at the Blues office wanted to share something fun: We recently had a customer report to us that both of their Airnotes had recently stopped working. The symptoms were that the unit could still turn on, charge, and could successfully report both temperature and humidity. However, every single air quality measurement submitted by both devices were zero, which indicates faulty hardware. For us, we found this scenario where two devices with the same owner sharing these symptoms was suspicious (Perhaps they were submerged in water? Perhaps they were both thrown onto the ground?) and we decided to investigate. These symptoms indicated that there either was no airflow within the unit (unlikely), or the laser within the sensor was damaged.
After the units made it back to the office and we confirmed that the air quality sensor was indeed “broken,” we swapped out the air sensor and fixed the devices. Afterward, we decided to crack open these air sensors and see if there was anything visible that could indicate the problem. This is what we found:
SPIDERS! These units must have been right next to each other and subject to the same hospitable environment for these critters. These very young spiders very likely made their way into the airflow intake of the Plantower sensors and couldn’t (or didn’t want to) escape after they’d grown up a bit. In any case, while we considered low airflow an unlikely culprit for this case, we’ve learned never to underestimate the unstoppable power of nature.
It should be noted that although we were able to diagnose this particular issue, we would not recommend our customers to rip out their own air sensors and pry open the housing to investigate similar problems - leave that to the experts to “debug” issues like this 
Neil Ozzie
PM - Experimental Solutions
Blues