Thank you for your reply! The power supply should have 5v out. A faint network light means the network light is off. The reason it looks faint is because it is the power light flooding in to the network light. If you are not getting a network connection to the Slingbox, the network light should blink. Being that it is off. tells me that it is an issue with the power supply. It may be issues with the amperage and not the voltage. Below is a link that will take you to where you can purchase a replacement power supply.
Hope this helps!
The Sling Moderation Team