Steve, take a look at [http://www.youtube.com/watch?v=IanSVeX6kXI|this video.]
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Steve, take a look at [http://www.youtube.com/watch?v=IanSVeX6kXI|this video.] if that does not work, utilize [http://www-pc.uni-regensburg.de/hardware/PC/DELL/GX150/manual/gx150sg/smdsktp.htm|this online service manual]. Hope this helps, good luck.