Too add to Dave's very good start of the assessment process (know what you are actually checking, one part of the system at a time) try this. With the cable detatched hold the inner cable just as it exits the shift pod (pull back the casing enough for your fingers to grab the inner). Not while tugging on the inner cycle the shifter through it's range. If your system has 9 "speeds" (rear cogs) there should be 8 clicks between the 9 index points. With the cable free and held by your fingers it should be easy to count the position/clicks. Since we are clueless as to what kind of shifter you have or even how many cogs are in the system we can't give much more specific advise. Andy