I had a similar situation last year. Not only did the DirecTV technician tell me that he could not go on my roof, he told me that even if he did, I could not get LOS to 99 or 103. That seemed odd to me, since I already had LOS to those slots. The reason I had called them was to replace the LNB5 with a LNB3 because I did not have LOS to 110 or 119 and realign the dish (I had had the roof replaced after the dish was installed, and never had it re-aligned - it worked, but signals were in the 70s and 80s when they could have been in the high 90s). I ended up calling an independent installer. He came the next day and did the work. Now, my signals are all above 95 on the 99, 101, and 103 slots.