I can't connect wired but can wirelessly

Hello,

I have a peoblem with my cisco linksys router. The wire doesn't work if I din't use that for a long time but the wireless works. Then I will have to unplug the router for a while then the wire works again.

I changed the wireless password then the problem happened. I did that through 192.168.1.1. Maybe I accidently click something wrong so that happened.

Please help me how to fix that.

Thanks