| Problem | Likely cause | Solution | |---------|--------------|----------| | Scanner not detected | USB 3.0 port / cable | Use USB 2.0 port, short cable | | “TWAIN source not found” | 32 vs 64-bit mismatch | Install both 32 & 64-bit TWAIN drivers | | Driver signing error (Windows 10/11) | Unsigned legacy driver | Disable driver signature enforcement temporarily (see below) | | Paper jam error always | Roller wear | Clean rollers, replace pad kit |