Pre-wired home lan, very slow speeds

[madcowpx]

I moved into a house prewired for internet. When I was connected only from the cable input, through my cable modem, then router, and using only wireless, everything worked fine. Yesterday I tried to plug the pre wired cables into my router and everything slowed to a crawl. The connections go from each room to a central box, in that box there are cables labled for each room, plus another labeled 'feed'. When I just plug the cables for the rooms I want to use the network in to the router (with it still connected to the modem) wireless still works fine, but wired does not work. I then plugged the 'feed' line into one of the router output ports (still leaving the modem plugged into the input) and the wired connections connect to the internet, but both wireless and wired download and upload speeds became very slow. Why did this happen and how can I fix it?

 

[Emerald]

can you provide a picture of the central box?

it almost sounds like it is wired for Phone not network.

 

[madcowpx]

I'll post a picture when I get off work tonight, but it is definitely the network. Blue cables and names match the places I had the connections installed. The phone is in a different part of the box and white wires.