Okidata C9300/C9500 Printing Issue Follow the steps below :-
1) Check and see if the image drum has been exposed to light for a period of time. If so, replace the I/D unit.
2) Check and see if the roller in the fuser is dirty. If so, replace the fuser unit.
3) Make sure the paper thickness setting is correct: Light: 64 g/m², Medium Light 64 to 74 g/m², Medium 75 to 90 g/m², Medium Heavy 91 to 104 g/m², Heavy 105 to 120 g/m², Ultra Heavy 121 to 203 g/m² Transparency.
4) Make sure the LED head assembly is properly connected to the connection board.
5) Make sure the +5V output correctly pins between the connection board and the LED head assembly. If not then replace the connection board accordingly.
6) Check the cable connections and replace the low-voltage power unit if necessary.
7) If the 34V output to the power connector pin 2 is not on the engine board (+34V: Pin 12, 13, 14), replace the engine board accordingly.
8) Replace the high-voltage power unit or belt cassette assembly if necessary.
9) Make sure the I/D unit terminal is properly connected to the contact assembly.
10) Replace the image drum if all the above steps do not result in normal printing quality.