Hey Harry,
I recommend using this as a basis to help users:
Router Troubleshooting Suggestions and TipsThis can be used mostly in router and AP posts. Even some camera items can be helpful as well.
Depending on what users post about and the problems they mention, the troubleshooting flow of the sticky helps to gain additional information from the users so we can get a better idea of there over all product and systems involved. We have seen were we thought the router was the problem, when doing more digging, we find there was problem at the ISP service/modem level.
Not all of the sticky may need to be used. Based on what users give in there initial post and the problem, use the sticky to help you and the user identify the real problem and find a solution. If all troubleshooting has been exhausted, then phone contact D-Link support maybe needed.
Glad ur back.