For your locatoin, 39 degrees latitude, your declination should be 6.1 degrees. With the
SG-2100, use 30-6.1=23.9 degrees. So, set your motor to 39(on the latitude scale, not elevation), set dish elevation to 24. That should get you close. Line it up on your TS, 87 degrees. If you are still way off, check that the back of the motor bracket, next to the mast, is parallel to the mast. I re-did someone's install recently where they had tightened down the bottom of the bracket more than the top, that set everything off about 5-8 degrees. The bottom of the bracket was buckled in. The only other thing I can think of is your lnbf arm might be off center.