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After reviewing all of the connections, over the course of more than 3 hours, the onsite technician reset the router. This time, that the router was reset, the reset button was held down for 30 seconds, as opposed to the 15 seconds which was recommended by the tech support agent.
Hopefully, the onsite representative will tell his teammates *and* the tech support center, that 30 seconds works better than 15 seconds. But, he may not tell, as he may be embarrassed that he had not tried that at the beginning of his visit, before spending the 3+ hours troubleshooting it as a connectivity issue.
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