SRS has a point but that's why I wanted to know if there was a log entry. If the system powered down for self-preservation, there will be a log entry to that effect. If the power supply shut down on it's own, there may be a log entry about starting up from an unknown condition or just the normal start up log entries. Meanwhile, if it stays up, it was just dirty and you'll have to clean it periodically. A toothbrush is goof for taking out the stuck on dust but don't brush your teeth with it afterward.