Let's be very systematic about this... 1. Make sure you have the mount guide rate set between 1X and 0.1X, if it is adjustable. 2. Check whether the mount has excessive backlash. Try to rock the axes back and forth with the brakes on. If it goes click-click back and forth with a noticeable amount of movement, then you need to adjust your worm gear engagement. Check both RA and Dec axes for this. The gears should be tight enough that there isn't excessive movement, yet not so tight that the motors bind. 3. If the mount has anti-backlash correction, turn it OFF. If set wrong it can completely mess up guiding. If set correctly and the delay is large enough it will cause a severe phase lag that will make guiding unstable. If you need backlash compensation, you should only do it in MaxIm DL. 4. Check your balance. When using a German Equatorial mount, you need the gear to be lifting the weight, not allowing it to drop. This means when the telescope is on the East side -- it is coming up -- that the counterweight should be adjusted so the telescope end is a little heavier. On the West side, the counterweight end should be a little heavier. If it isn't set this way, the telescope will move in little jerks as the gears bounce back and forth, and it will be impossible to guide. 5. Make sure your drive is behaving itself. Unplug the autoguider cable from the mount. Go to the Guide tab and take an image and make sure you have a good bright guide star with an exposure time of 1 second or less. Turn on "Watch Star" and start the guider. Grab the mount's hand paddle, and watch the star and the X Error, Y Error data coming from the Guide tab. Try to guide it manually. If you find you cannot do this, there is something seriously wrong with the mount. 6. If all is good so far, stop guiding and plug the cable back in. 7. Click the Settings button. For the X Axis Set Cal Time to 10 and backlash to 0. Do the same for Y Axis. Set Aggressiveness to 7. Make sure Auto Dark, Enable X Axis, and Enable Y Axis are ON. If you have a TC237 guide chip set Binning to 2; otherwise set it to 1. Hit the Reset button for the subframe. Click the More button and set the following parameters under Guiding: Minimum Move X 0.01, Minimum Move Y 0.01, Maximum Move X 2, Maximum Move Y 2, Delay after correction 0.1. Make sure all Output Enables are ON. Make sure Offset Tracking is Cleared. Enable the Track Log and set it up to save in a file that you can find (if you can't get guiding going I may ask you to send it to me). Click OK. Click OK. 8. Take an exposure 1 second or less with the Guide tab and make sure you have a nice, bright star, reasonably near the center of the chip. 9. Start the calibration cycle. Watch the star. It should move in one directly, move back again, move at right angles, and move back again. Look at the numbers that the display window on the Guide tab shows you. Make sure the star moved at least 10 pixels in each direction, and that it returned to its starting point. If the star does not move very far, then increase the corresponding Cal Time value in the settings (first motion is X, last is Y). If it's so fast that the star goes off the chip, then check whether the mount's guide speed is higher than 1X. If you get any error messages, stop and figure out why; otherwise the calibration will be invalid. 10. Switch to Guide mode. Start tracking. Watch the star, and make sure it behaves itself. If it starts bouncing back and forth, then reduce the Aggressiveness setting. If you are having trouble, note which axis it is -- Right Ascension or Declination. 11. If you are having trouble in RA, check the mount balance again. 12. If you are having trouble in Declination, you might have a stiction problem. This is a tendency for the mount to continue moving forwards when the guide motor reverses direction. Put in a high power eyepiece eyepiece and try rocking a star back and forth in Declination with the hand paddle; if you see the star move in the wrong direction when you try to reverse, you've got stiction. The solution for stiction is to note which way the star is drifting in declination. Go to the Settings/More and DISABLE the guider output that pushes the star in the direction of the drift. That way it will only ever push in one direction -- against the drift. 13. If the eyepiece test shows a LOT of backlash -- the star just sits there for a few seconds before reversing, then we can try the backlash adjustment in MaxIm DL. Don't worry about RA backlash -- the sidereal tracking eliminates that. Only Dec matters (the Y direction if your guider cable is wired normally). Watch the star in the eyepiece and time (with a stopwatch if possible) how long it takes for the star to reverse. Enter that value (in seconds) LESS 1/2 SECOND FOR SAFETY into the backlash setting. If you put in too high a number, guiding will utterly fail -- it is way better to have 0 than too much. 14. If after all this fails, send me your track log. Hope this helps!