Internet Connection Problem???

[Shawn P]

I am having problems with Internet Connection. Setup- Modem to Linksys Router(Wired) to SMC Switch to Belkin Pre-N Wireless Router( Access Point). From switch to wireless router 1-4 port numbers and NOT connected WAN(Internet) Turn off DHCP to make Wired Router assign DHCP. Even Belkin Pre-N Router is connected, Internet work with using wireless but after sometime Internet stops working.
Is possible to add Wireless Router to make as Access Point after or before the SMC Switch?
How to test the Wireless Router-to check if it is bad or going bad?
I cant able to access Wireless Router with Default Gateway. Default Gateway sign on to Wired Router.