Get it at random times, usually for less than 10 seconds though. and i always hope that its not because the bench went out or is on its way out. last time it went out it gave no warning, and i sat there for like 5 minutes and waited for this HC hangup to clear, and it never did. aborted the test, went to manual mode and the readings were off the charts wrong. called up the service tech to bring me a new bench but it still sucks being down for a week or more while they get someone out to see why.