The slot for the second memory card on the motherboard adjacent the two main chips and the heat sink fan is not working - I had an overheating problem, got a new main heat sink assembly and fan and soldered a jumper wire and loop across HS2 on the board from the top. The original card in the second slot (adjacent the heat sink devices and the HS-2 slot) did not work when I restarted the machine; removing that card allowed the machine to boot up and operate, although slowly (with only 256 MB). I replaced the original and second cards with Kingston 1-G cards, but the second card slot does not work either. Nothing looks amiss from above. Could my soldering the jumper across HS2 have goofed up something under the motherboard, or is there likely another problem? Please advise on analysis and repair. Thanks.