Most free PDFs of the will also include a component placement diagram (bottom layer and top layer). This is critical because many components have no silkscreen label on the actual PCB; you need the placement diagram to locate, say, R2202.
Professional repair communities maintain cloud drives of schematic diagrams. Join channels labeled "GSM Free Schematics" and search for RM-647 (the Nokia 1280’s product code). Schematic Diagram Nokia 1280 Free