I recently broke my belkin router <link>.
Since the warranty is already over I thought I would post pictures of the inside.
On the underside of the circuit board you can see some sand colored gunk but its probably not significant. An interesting note is that there is a second internal antenna.
In the pic below I have cropped the relevant area. The connection labeled below the shiny chrome plated chip labeled CON 1 is where the external antenna is located. To the right of the chrome plated chip is a simple length of sheet metal. This is the internal antenna. Its labeled CON2 but the label is obscured in this shot.
Update: the culprit was my surge protector. Here's how i fixed it.