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When you say you made sure there was power to the unit, did you use a multimeter and test the voltage coming off the power cable itself?
I ask because, usually when the 498 series loses power like this and the unit is several years old. Its almost always due to the power cable failing due to corrosion from being exposed to the elements ( especially salt water and humidity ) over time. Usually replacing the power cable does the trick http://amzn.to/1UM2Wcn
So if you havent replaced the power cable as of yet, I would start there. And that should fix the issue.
I strive to provide great service, and greatly appreciate a 5 star rating clicked and submitted when you are satisfied.. I always answer follow up questions.Dustin S.Senior Technician and Network Switching Systems Operator / Maintainer.
Hello again, I never heard back from you.
Did you still need help with this issue or did my steps help you?