1 | Open the ADF top door and remove the pick roller cover. |
2 | Check the black wire with a terminal (A) (located under a screw contacting a metal plate) near the pick mechanism drive belt. Move the black wire back and forth to make sure the metal terminal is touching the metal plate. Take a multimeter and measure the resistance from the ADF frame's metal plate to make sure it has low resistance, while simultaneously moving the wire back and forth. |
3 | If the connection is good or has low resistance, check the small metal bracket (B) that connects the ADF roller shaft and spring assembly. Open the top door and check to make sure that the bracket is securely in place and has contact on the metal shaft. If the scanner has seen frequent use, there could be a worn spot on the shaft, as seen in the image. This would indicate very good contact. |
4 | If the connection is good, remove the front and rear ADF covers. |
5 | Lift up the document feeder tray. There should be two screws with cables (C) on the lift plate (one at each end). Measure the resistance from the ADF frame ground to each screw. If the resistance is low, proceed to the next step. |
6 | Locate the metal-coated Mylar grounding strips (D) that run from the flatbed up into the ADF. There are two of these strips to be found on the printer (one on each side). Measure the resistance between the strip and main printer frame ground. |
7 | If there are no loose connections, measure the resistance from the ADF frame to the printer frame. One suggestion would be to measure the resistance between the system card cage and the metal plate of the ADF frame under the ADF document feeder. |
8 | Should the measurement read a high resistance and no other issues are found, then replace the entire ADF assembly. |