Router stopped connecting to internet?

Description

I have 2 routers in my house. the primary router is a Linksys Cisco EA6500 and the secondary router is a WRT 54G v2.2. My secondary router also has Tomato (custom OS) installed on it. Both worked splendidly in my previous house (around a year ago)

Problem

My secondary router which i use to extend signal to the second floor of my house has mysteriously stopped working with ALL devices, it doesn't matter whether it is plugged in via ethernet, or connected wirelessly. It just doesn't  connect to internet. So far i have only tried reseting both routers. Each time i reset the routers, the primary router ends up working fine where as the secondary doesn't connect to the internet at all.

I do understand that my secondary router is very old, but i don't want to have to go and buy another router.

 

If you need anymore details just ask.

 Thanks in advance