The power socket on my old PCG-FX203 broke, so I bought a motherboard from ebay from another FX series laptop, and unsoldered the power socket from it. I then opened up the FX203, and replaced the broken socket. However, the problem still persists. I have to hold the power cable into the socket otherwise no connection is made, even though the cable clips into place. When soldering the power socket into place, I noticed that the negative connection coming out of the socket did not appear to be connected to any components on the mboard, instead there is a short PCB track which just ends without connecting to anything. I am wondering if this track is supposed to contact with the metal chassis of the laptop and be grounded in that way. Any ideas?