Thank you for using our online answers forum. I am sorry to hear your having issues with your Slingbox not powering up. It is hard to say exactly what could be causing the issue without a little more information. Does the box now power up at all? Are you getting any lights on the box? What kind of Slingbox do you have? How long has this been going on for? What is the brand of your power supply chord? Below I have provided a few links to help try and troubleshoot your issue a little further, also feel free to call our support center at 877-GO-SLING.
Here are a few links to troubleshoot your issue further.
Hope these help, feel free to reply back with any other questions or concerns you might have!
The Sling Moderation Team