To clarify further, if John was 24 when married in 1890 then he was born 1866/67 and sure enough there is a birth in Lincoln, registered Dec.1867 of a John Robert Robinson. If we assume his father was about 20-25 when he was born, that would mean William was born about 1840-50. However, the easiest thing to do would be to get the birth certificate of John Robert Robinson, Dec.1867 Lincoln 7a 444.
Lizzie
Modified - Getting the birth certificate would not only give his father's name, but also his mother's. Apart from the fact that William is stated as deceased on John's marriage certificate, it is impossible to know when he died. It could have been anytime from 1867 to 1890. I can't find a William Robinson, born before 1850 who was a printer on any census.