The usual advice is to be sure your mast (even if it is 6" long) in perfectly vertical. Use a bubble level on all the pipe's sides before clamping on the dish. It is very hard to get elevation and skew correct without this. The numbers for you Zip code in the recorder are accurate enough for a start. I assume you are in the Menu+6+1+1 window. Menu+6+1+3 show the values for transponders (TP) 14 15 16 21 so any of those can be used--for 129 only TP21 is shown, those below 17 are spot beams.
Get the center 119 LNB working first, foil covers on the outside LNBs may help. The azimuth given is magnetic and you can use you property lines and your declination to set that. Otherwise you will have to sweep the azimuth in 2 deg steps at a fixed elevation and try say 2 degrees higher and lower elevations until you get a signal. Then tweak the azimuth and elevation for the best signal. Be sure it has locked on to 119. Depending on the receiver and dish model you may be able to run a single line from 119 to the receiver.
On a triple LNB use the numbers for the Dish System 300. With the nominal skew you should then get both 110 and 129 without the covers. If they differ noticeably then a further slight skew adjustment may help to balance them. A slight elevation shift with let you balance 119 against the average of 110 and 129. Repeat once. If they are not good then you should look again for obstructions or loose bolts on the base or misread angles. Remember the dish is a mirror and the arm is below the axis of the dish, so it is looking above the normal to dish by say 15 deg. Be content with numbers above 50, like 60 unless you have a big dish.
-Ken
