Its unfortunate that your having these issues with the Slingbox. I noticed in your post that you have had switched out the switch and corresponding cables and still it would not connect. But, have you tried to connect the Slingbox directly to the router, to see you can get a solid network connection on the Slingbox?
If not, I would suggest connecting the Slingbox directly to the router and see what happens. Also, I have provided an article that may provide some mroe assistance regarding this issue, please take a look.
Hope this helps,
Answers Forum Moderation Team