Align from scratch.
Aligning a Slimline (or any other) dish from scratch can be a daunting task. However it can be done if you’re patient. Go to www.dishpointer.com and determine the magnetic azimuth, elevation and tilt settings for your location. Use a level to assure that your mast is perfectly plumb. Set the elevation and tilt to the markings on the dish. Use a compass and set the azimuth about 10 degrees East of the recommended magnetic setting. Tune your receiver to display the signal strengths on the 101 satellite, then choose the green signal bars from the link in the lower right corner of the signal screen. Slowly, a degree at a time, move the dish to the West until you get signals on the 101 satellite. All 32 (with a few of exceptions) of the transponders should light up. Fine tune for maximum signal. Lock down the main bolts.
At this point a procedure called “dithering” is employed to fine tune to the 101 satellite. You can try skipping this and going to the next step, assuming you have a Slimline dish..
Tune your receiver to display the signal strengths on the 99c satellite, then choose the green signal bars from the link in the lower right corner of the signal screen. Use a level to plumb the dish mast (essential) Tighten the main clamps and
loosen the fine tuning apparatus on one axis at a time. Have someone watch (cell phones are handy to advise) while you adjust the fine tuning screw on the azimuth setting. Go slow, only tiny amounts will make a big difference.
You'll soon know if you're going the wrong way and a couple of turns will likely max out the improvement. Lock the bolts and do elevation next. It should not be necessary to adjust the tilt. You should be able to get the signals into the 90's quite easily.