Complex sentence: The band had their ups and downs on the charts throughout the 1980s, landing only sporadic Top 10 hits, however, they had accumulated enough hits for a Greatest Hits package by 1990, and were very successful on the touring circuit.
Split into simpler sentences: The band had their ups and downs on the charts throughout the 1980s, landing only sporadic Top 10 hits. However, by 1990 they had accumulated enough hits for a Greatest Hits package, and were successful on the touring circuit.