The above posts seem to discuss this well. It is very similar to this week’s simulation: assuming that a machine failed due to machine failure (or nearby machine malfunction), it would most likely not require a new IQ, OQ, PQ because the machine would most likely return to the functional condition when the parameters are changed back to the original state. Revalidation would be required if the machine moved, or possibly a recalibration, if there are errors or fragile parts/sensors.