Bought printer second hand, don’t have all the manuals. Worked fine for months, but do need to change colour cartridge, but have change b&w one & prints fine….or did. After mild paper jam, the middle light of the 3 on the top right of the printer keeps flashing. Solid light indicates – needs paper. Light not on, when works fine. It doesn’t need paper & turning off & on doesn’t clear it, can’t see a jam but can’t really get into printer. Just sits there flashing & won’t print anything. What do I do? Any suggestions welcomed.