Rubbing alcohol used for cleaning is probable cause for Merlin engine shutdown on March 18 launch.
https://techcrunch.com/2020/04/22/s...sed-by-cleaning-fluid-according-to-elon-musk/
https://techcrunch.com/2020/04/22/s...sed-by-cleaning-fluid-according-to-elon-musk/
Musk said the cause of the Merlin failure was a “mall amount of isopropyl alcohol (cleaning fluid) [that] was trapped in a sensor dead leg & ignited in flight.” ..................
Based on Musk’s explanation, it sounds like some was accidentally trapped in the sensor housing for a pressure valve in the Merlin’s fluid systems, and then it caught fire when the engine was ignited. That likely wasn’t enough to damage the engine, but told the sensor that heat levels were exceeding acceptable limits and caused a shutdown.