• Code: 938.01 ... 938.10
• Description: 938.01 Electronics Hardware Error The system board is not in the correct level. 938.02 Electronics Hardware Error A system board timeout error has occurred. 938.03–938.04 Electronics Hardware Error A communication error has occurred. 938.05–938.08 Electronics Hardware Error Under-voltage was detected. 938.09 Electronics Hardware Error The printhead PLL failed to achieve lock. 938.10 Electronics Hardware Error The humidity sensor failed.
• Remedy: • POR the printer. • If the error persists, replace the system board.

• Code: 938.11 ... 938.14
• Description: 938.11–938.14 Electronics Hardware Error A cartridge sensor failed.
• Remedy: 1 a. Power off the printer. b. Enter the Diagnostics mode, (press and hold 3 and 6, while turning on the printer). c. Select Base Sensor Test. d. Select the failing sensor: e. Remove all the cartridges. f. Defeat the front access door switch with a screwdriver as shown. g. Depress the arm of the failing sensor. Replace the cartridge. Go to step 2. Error code Sensor 133.01 K TMC sensor 133.02 C TMC sensor 133.03 M TMC sensor 133.04 Y TMC sensor Does the sensor go from “Open” to “Close?” 2 Turn the printer off and open the system board shield. Check the cables in the indicated connectors for proper connection to the system board. The cables are interchangeable on the terminals, so check all four cables for any 133.xx error. Are the cables properly connected? 3 Check the cables in the indicated connectors for proper connection to the system board. 133.01 Black—D (JCMKM1) 133.02 Cyan—C (JCMCY1) 133.03 Magenta—D (JCMKM1) 133.04 Yellow—C (JCMCY1) Are the cables properly connected? Go to step 4. Reseat the cable. 4 Check the cables in connectors JCMKM1 and JCMCY1 for damage, and then remove all four cartridges and check the other ends of the cables connected to the sensors on the memory blocks. 133.01 Black—B (JCMKM1) 133.02 Cyan—A (JCMCY1) 133.03 Magenta—B (JCMKM1) 133.04 Yellow—A (JCMCY1) Is either cable damaged? Replace the cable. Go to step 3. 5 Replace the indicated cartridge memory block and cable. See “Cartridge memory block removal”. Set up cartridge to force a TMC. 1. Take the cartridge indicated by the error code, and rotate the developer input gear (E) clockwise to locate the tab as indicated. 2. Rotate the toner metering paddle cam (G) up to force the tab (F) until it sticks out. Problem solved. Replace the system board. See “System board removal”. 3. Rotate the developer input gear clockwise until the tab (H) is up against the tab on the larger gear (J). Print two demo pages: 1. Replace all cartridges. 2. Turn on the machine. 3. Select Menu > Reports > Print Demo > Demo Page. 4. Do step three again to get the second demo page. Does this fix the problem?

• Code: 938.15
• Description: Electronics Hardware Error An output bin sensor not connected error occurred.
• Remedy: 1 Is the bin-full flag damaged? Replace the bin-full flag. See “Bin-full flag removal”. Go to step 2. 2 Turn the printer off, and open the system board shield. Check the cable in connector JTCVR1 for proper connection to the system board. Is the cable properly connected? Go to step 3. Reseat the cable. 3 Check the cable in connector JTCVR1 for damage. Is the cable damaged? Replace the bin-full and output beacon cable. To access the cable, see “AIO top cover removal”. Go to step 4. 4 Remove the bin-full sensor. See “Bin-full sensor removal”. Is the cable properly connected? Go to step 5. Reseat the cable. 5 Replace the bin-full sensor. See “Bin-full sensor removal” Does the error reoccur? Replace the system board. See “System board removal”. Problem solved.

• Code: 938.16
• Description: Electronics Hardware Error An MPF paper out sensor not connected error occurred.
• Remedy: 1 Turn the printer off, and open the system board shield. Check the cable in connector JMPF1(MPF sensor cable) for proper connection to the system board. Is the cable properly connected? Go to step 2. Reseat the cable. 2 Check the cable in the JMPF1(MPF sensor cable) connector for damage. Is the cable damaged? Replace the MPF sensor cable. See “MPF sensor cable”. Go to step 3. 3 Remove the MPF sensor plate assembly. See “MPF sensor plate assembly removal”. Check the cable connected to the sensor. Is the cable properly connected? Go to step 4. Reseat the cable. 4 Replace the MPF sensor plate assembly. See “MPF sensor plate assembly removal”. Does the error reoccur? Replace the system board. See “System board removal”. Problem solved.

• Code: 938.18
• Description: Electronics Hardware Error A waste toner sensor not connected error occurred.
• Remedy: 1 Turn the printer off, and open the system board shield. Check the cable in connector JWTB1 for proper connection to the system board. Is the cable properly connected? Go to step 2. Reseat the cable. 2 Check the cable for damage. Is the cable damaged? Replace the waste toner cable. See “Waste toner cable removal”. Go to step 3. 3 Remove the waste toner sensor. See “Waste toner sensor removal”. Check the cable connected to the sensor. Is the cable properly connected? Go to step 4. Reseat the cable. 4 Replace the waste toner sensor. See “Waste toner sensor removal”. Does the error reoccur? Replace the system board. See “System board removal”. Problem solved.

• Code: 938.19
• Description: Electronics Hardware Error A waste toner full sensor not connected error occurred.
• Remedy: 1 Open the left access door assembly, and check the duplex assembly gears for damage. Is the duplex assembly damaged? Replace the duplex assembly. See “Staging paper path reference edge assembly removal”. Go to step 2. 2 Turn the printer off, and open the system board shield. Check the cable in connector JDUPL1 for proper connection to the system board. Is the cable properly connected? Go to step 3. Reseat the cable. 3 Check the cable for damage. Is the cable damaged? Replace the cable. See “Staging paper path reference edge assembly removal” to access the cable. Go to step 4. 4 Remove the rear cover and the left cover. See “Rear cover removal” and “Left cover removal”. Check the cable connection to the duplex motor. Is the cable connected correctly to the staging motor? Go to step 5. Reseat the cable. 5 Replace the reference edge assembly. See “Staging paper path reference edge assembly removal”. Dose the error reoccur? Replace the system board. See “System board removal”. Problem solved.

• Code: 938.20
• Description: Electronics Hardware Error A duplex motor failure occurred.
• Remedy: 1 Open the left access door assembly, and check the duplex assembly gears for damage. Is the duplex assembly damaged? Replace the duplex assembly. See “Staging paper path reference edge assembly removal”. Go to step 2. 2 Turn the printer off, and open the system board shield. Check the cable in connector JDUPL1 for proper connection to the system board. Is the cable properly connected? Go to step 3. Reseat the cable. 3 Check the cable for damage. Is the cable damaged? Replace the cable. See “Staging paper path reference edge assembly removal” to access the cable. Go to step 4. 4 Remove the rear cover and the left cover. See “Rear cover removal” and “Left cover removal”. Check the cable connection to the duplex motor. Is the cable connected correctly to the staging motor? Go to step 5. Reseat the cable. 5 Replace the reference edge assembly. See “Staging paper path reference edge assembly removal”. Dose the error reoccur? Replace the system board. See “System board removal”. Problem solved.

• Code: 938.21
• Description: Electronics Hardware Error A staging motor failure occurred.
• Remedy: 1 Turn the printer off, and open the system board shield. Check the cable in connector JSTAG1 for proper connection to the system board. Is the cable properly connected? Go to step 2. Reseat the cable. 2 Check the cable for damage. Is the cable damaged? Replace the cable. See “Staging paper path reference edge assembly removal” to access the cable. Go to step 3. 3 Remove the LVPS. See “Low-voltage power supply (LVPS) removal”. Check the cable connection to the motor. Is the cable connected correctly to the staging motor? Go to step 4. Reseat the cable. 4 Replace the staging paper path reference edge assembly. See “Staging paper path reference edge assembly removal”. Dose the error reoccur? Replace the system board. See “System board removal”. Problem solved.