So the second floor of my house is already wired up with cat5 (not cat5e as the house predates cat5e) wires. I recently decided to move my modem to the basement and hooked up all the cat5 drops to a switch. When It came to the only room that has a desktop in, my switch indicated that the connection was up with a 100mbps speed and full duplex enabled, this was when the desktop is OFF with the power cable still connected to the wall outlet. When I turn on the desktop the connection link goes from up to down and everything indicates to nothing as if there isn't any connection what so ever, but the patch cord is connected to both the keystone jack and the ethernet adapter on the desktop. Any ideas??
The drop is on the second floor fyi.
Switch: Netgear GS725Tv3
Modem: SmartRG SR505n