If you are not able to connect locally or remotely to the Slingbox and you already tried to perform a Reset and that did not help, I recommend to use a different computer to run the Setup at slingbox.com, if you are still not able to do it, try the steps that you will find at the article bellow. We also need to get some information about the connections to the Slingbox, is it hardwired to the router or are you using a power or a wireless bridge? Also, what's the operating system of your computer? Have you tried a different power supply?
Let us know how that works