reply to crazydog
Re: SB5101U Can't connect, SB6121 can, Moto support says signals Your upstream at 37 dBmV is on the very low end. 35 dBmV is the suggested lowest limit. Your SB6121 may be more forgiving than your SB5101U if your upstream decides to slide even lower than 35 dBmV. You need to get your upstream in a preferable range between 40 - 45 dBmV.
Well, the tech came out. He said the signals were great for my location....I'm hesitant to call Motorola back, but I'm also hesitant to just sell the modem if it may be broken.