Canon Pixma MP500

That is a line feed error (6000) It also should be flashing 3 times for this error on the on/off button.
This could be
1. Timing sensor unit QM2-2683
2. Timing slit disk film QC1-6229
3. Feed roller ass'y QL2-0925
4. Platten unit QM2-2923
5. Logic board ass'y QM2-3078
6. Paper feed motor QK1-1502