• Code: 10-101, 10-102, 10-103
• Description: Lead Edge Late to Fuser Exit Switch Entry RAP 10-101 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a simplex sheet. 10-102 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a duplex sheet side 1. 10-103 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a duplex sheet side 2.
• Remedy: • If the speed of the machine is 35-55 ppm, go to 10-101A, 10-102A, 10-103A Lead Edge Late to Fuser Exit Switch RAP. • If the speed of the machine is 65-90 ppm, go to 10-101B, 10-102B, 10-103B Lead Edge Late to Fuser Exit Switch RAP.

• Code: 10-101A, 10-102A, 10-103A
• Description: Lead Edge Late to Fuser Exit Switch RAP (35-55 ppm) 10-101 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a simplex sheet. 10-102 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a duplex sheet side 1. 10-103 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a duplex sheet side 2.
• Remedy: NOTE: The door interlock switch must be cheated when checking +24V components. Enter dC330 code 10-100 fuser exit switch, S10-100. Press Start. Manually actuate the switch with a piece of paper. The display changes. Y↓N→Go to Flag 1. Check S10-100. Refer to: • GP 13 How to Check a Switch. •. • P/J35, IOT PWB. • 01D +3.3V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Fuser exit switch, (35-55 ppm) PL 10.8 Item 11. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-065 vacuum transport fan, MOT10-065.. Press Start, The fan runs. Y↓N→Go to Flag 2. Check MOT10-065. Refer to: • GP 10 How to Check a Motor. •. • P/J5, IOT PWB. • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Short paper path assembly, PL 10.25 Item 1. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 04-010 main drive motor. Press Start. Add code 08-070 registration clutch, CL08-070. Press Start. NOTE: The clutch will switch off after 5 seconds. The jam clearance knob 4c, PL 8.15 Item 10, rotates. Y↓N→Go to Flag 3. Check CL08-070. Refer to: • GP 12 How to Check a Solenoid or Clutch. • P/J5, IOT PWB. • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Registration clutch, (35-55 ppm) PL 8.15 Item 7. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 08-150 registration sensor, Q08-150. Press Start. Manually actuate the sensor. The display changes. Y↓N→Go to Flag 4. Check Q08-150. Refer to: • GP 11 How to Check a Sensor. •. • P/J5, IOT PWB. • 01D +3.3V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Registration sensor, (35-55 ppm) PL 8.15 Item 3. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Check the following components, refer to GP 7: • Registration roll, PL 8.15 Item 9. • Roll assembly on the short paper path assembly, PL 10.25 Item 1. • Check the detack corotron and the connection to the HVPS. Refer to 09-060 HVPS Fault RAP • The drive gear on the fuser module, (35-55 ppm) PL 10.8 Item 1. • The fuser drive gear on the main drives module, (35-55 ppm) PL 4.17 Item 10. • Fuser web motor and the fuser web, 10A Fuser Web Motor RAP. • Check the drives plate on the registration clutch for damage and contamination. Refer to the replacement procedure. • If the fault still occurs, the +24V supply from the LVPS may be faulty. Install a new LVPS, PL 1.10 Item 3.

• Code: 10-101B, 10-102B, 10-103B
• Description: Lead Edge Late to Fuser Exit Switch RAP (65-90 ppm) 10-101 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a simplex sheet. 10-102 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a duplex sheet side 1. 10-103 The lead edge of the paper failed to actuate the fuser exit switch within the correct time after the registration clutch was energized for a duplex sheet side 2.
• Remedy: NOTE: The door interlock switch must be cheated when checking +24V components. Enter dC330 code 10-100 fuser exit switch, S10-100. Press Start. Manually actuate the switch with a piece of paper. The display changes. Y↓N→Go to Flag 1. Check S10-100. Refer to: • GP 13 How to Check a Switch. •. • P/J35, IOT PWB. • 01D +3.3V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Fuser exit switch, (65-90 ppm) PL 10.10 Item 11 • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-065 vacuum transport fan, MOT10-065.. Press Start, The fan runs. Y↓N→Go to Flag 2. Check MOT10-065. Refer to: • GP 10 How to Check a Motor. •. • P/J5, IOT PWB. • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Short paper path assembly, PL 10.25 Item 1. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 04-010 main drive motor. Press Start. Add code 08-070 registration clutch, CL08-070. Press Start. NOTE: The clutch will switch off after 5 seconds. The jam clearance knob 4c, PL 8.17 Item 10, rotates. Y↓N→Go to Flag 3. Check CL08-070. Refer to: • GP 12 How to Check a Solenoid or Clutch. • P/J5, IOT PWB. • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Registration clutch, (65-90 ppm) PL 8.17 Item 7. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 08-150 registration sensor, Q08-150. Press Start. Manually actuate the sensor with a piece of paper. The display changes. Y↓N→Go to Flag 4. Check Q08-150. Refer to: • GP 11 How to Check a Sensor. •. • P/J16, IOT PWB. • 01E +5V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Registration sensor, PL 8.17 Item 3. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Check the following components, refer to GP 7: • Registration roll, (65-90 ppm) PL 8.17 Item 9. • Roll assembly on the short paper path assembly, PL 10.25 Item 1. • Check the detack corotron and the connection to the HVPS. Refer to 09-060 HVPS Fault RAP • The drive gear on the fuser module, (65-90 ppm) PL 10.10 Item 1. • The fuser drive gear on the main drives module, (65-90 ppm) PL 4.12 Item 10. • Fuser web motor and the fuser web, 10A Fuser Web Motor RAP. • Check the drives plate on the registration clutch for damage and contamination. Refer to the replacement procedure. • If the fault still occurs, the +24V supply from the LVPS may be faulty. Install a new LVPS, PL 1.10 Item 3.

• Code: 10-107, 10-108, 10-109, 10-110
• Description: Trail Edge Late from Fuser Exit Switch RAP 10-107 The trail edge of the paper failed to de-actuate the fuser exit switch within the correct time after the trail edge at the registration sensor, for a simplex non inverted sheet. 10-108 The trail edge of the paper failed to de-actuate the fuser exit switch within the correct time after the trail edge at the registration sensor, for a simplex inverted sheet. 10-109 The trail edge of the paper failed to de-actuate the fuser exit switch within the correct time after the trail edge at the registration sensor, for a duplex sheet side 1. 10-110 The trail edge of the paper failed to de-actuate the fuser exit switch within the correct time after the trail edge at the registration sensor, for a duplex sheet side 2.
• Remedy: NOTE: The door interlock switch must be cheated when checking +24V components. Enter dC330 code 10-100 fuser exit switch, S10-100. Press Start. Manually actuate the switch with a piece of paper. The display changes. Y↓N→Go to Flag 1. Check S10-100. Refer to: • GP 13 How to Check a Switch. • (35-55 ppm). (65-90). • P/J35, IOT PWB. • 01D +3.3V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Fuser exit switch, (35-55 ppm) PL 10.8 Item 11 or (65-90 ppm) PL 10.10 Item 11 • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-045 inverter path solenoid, SOL10-045. Press Start. The solenoid energized. Y↓N→Go to Flag 2. Check SOL10-045. Refer to: • GP 12 How to Check a Solenoid or Clutch. • (35-55 ppm). (65-90 ppm). • P/J5, IOT PWB • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter path solenoid, PL 10.11 Item 14. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-030 inverter motor, MOT 10-030. Press start. The jam clearance knob, 2B, PL 10.15 Item 13, is stationary and the motor can be heard. Y↓N→The jam clearance knob, 2B, PL 10.15 Item 13, rotates counterclockwise. Y↓N→Go to Flag 3. Check MOT10-030. Refer to: • GP 10 How to Check a Motor. • P/J4, IOT PWB. • P/J45, P/J55 inverter motor driver PWB • 01G +24V Distribution RAP. • 01E +5V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter motor, PL 10.11 Item 11. • Inverter motor driver PWB, PL 10.11 Item 22. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Install a new inverter motor driver PWB, PL 10.11 Item 22. Check the following components, refer to GP 7: • The drive gear on the fuser module, PL 10.10 Item 1. • The fuser drive gear on the main drives module, (35-55 ppm) PL 4.17 Item 10, (65-90 ppm) PL 4.12 Item 10. • Fuser web motor and the fuser web, 10A Fuser Web Motor RAP. • Drives between inverter and the main drives module, PL 10.15. • Post fuser exit roller, PL 10.12 Item 9. NOTE: Excessive post fuser exit roll wear causes buckle between the fuser and the inverter assembly. This can cause severe ripple on the trail edge of A3 (11x17 inch) sheet and paper jams. • Upper baffle, (35-55 ppm) PL 10.12 Item 23, (65-90 ppm) PL 10.12 Item 22. • Baffle guide, PL 10.13 Item 3. If the fault still occurs, the +24V supply from the LVPS may be faulty. Install a new LVPS, PL 1.10 Item 3.

• Code: 10-120, 10-121, 10-126
• Description: IOT Exit Sensor RAP 10-120 The lead edge of the paper failed to reach the IOT exit sensor within the correct time after the trail edge at the fuser exit switch for an inverted sheet. 10-121 The lead edge of the paper failed to reach the IOT exit sensor within the correct time after the trail edge at the fuser exit switch for an non inverted sheet. 10-126 The trail edge of the paper failed to clear the IOT exit sensor within the correct time.
• Remedy: NOTE: Ensure that the door interlock switch is cheated when checking +24V components. Enter dC330 code 10-120 IOT exit sensor, Q10-120. Press Start. Manually actuate the sensor. The display changes. Y↓N→Go to Flag 1. Check Q10-120. Refer to: • GP 11 How to Check a Sensor. • (35-55 ppm). (65-90 ppm). • P/J5, IOT PWB. • 01D +3.3V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • IOT exit sensor, PL 10.11 Item 13. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-050 inverter nip solenoid, SOL10-050. Press Start. The solenoid energises. Y↓N→Go to Flag 2. Check SOL10-050. Refer to: • GP 12 How to Check a Solenoid or Clutch. • (35-55 ppm). (65-90 ppm). • P/J5, IOT PWB. • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter nip solenoid, PL 10.11 Item 6. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-045 inverter path solenoid, SOL 10-045. Press Start. The solenoid energizes. Y↓N→Go to Flag 3. Check SOL 10-045. Refer to: • GP 12 How to Check a Solenoid or Clutch. • (35-55 ppm). (65-90 ppm). • P/J5, IOT PWB • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter path solenoid, PL 10.11 Item 14. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-030 inverter motor, MOT10-030. Press Start. The jam clearance knob, 2B, PL 10.15 Item 13, is stationary and the motor can be heard. Y↓N→The jam clearance knob, 2B, PL 10.15 Item 13, rotates counterclockwise. Y↓N→Go to Flag 4. Check MOT10-030. Refer to: • GP 10 How to Check a Motor. • P/J4, IOT PWB • P/J45, P/J55 • 01G +24V Distribution RAP • 01E +5V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter motor, PL 10.11 Item 11. • Inverter motor driver PWB, PL 10.11 Item 22. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Install a new inverter motor driver PWB, PL 10.11 Item 22. Check the following components, refer to GP 7: • Idler roll, PL 10.12 Item 15. • Upper baffle, (35-55 ppm) PL 10.12 Item 23, (65-90 ppm) PL 10.12 Item 22. • Double exit nip roll, PL 10.11 Item 8. • Exit shaft assembly, PL 10.13 Item 4. • Nip split shaft assembly, PL 10.11 Item 4. • The drive gear on the fuser module, (35-55 ppm) PL 10.8 Item 1, (65-90 ppm) PL 10.10 Item 1. • The fuser drive gear on the main drives module, (35-55 ppm) PL 4.17 Item 10, (65-90 ppm) PL 4.12 Item 10. • Check the IOT exit sensor mounting bracket on the nip roll guide, PL 10.11 Item 10. The bracket holds the IOT exit sensor in the correct position, PL 10.11 Item 13. If the fault still occurs, the +24V supply from the LVPS may be faulty. Install a new LVPS, PL 1.10 Item 3.

• Code: 10-132, 10-133, 10-134
• Description: Lead Edge Late to Inverter Sensor RAP (65-90 ppm) 10-132 The lead edge of the paper failed to actuate the inverter sensor within the correct time after the fuser exit switch is made, for a simplex sheet. 10-133 The lead edge of the paper failed to actuate the inverter sensor within the correct time after the fuser exit switch is made, for a duplex 1 sheet. 10-134 The lead edge of the paper failed to actuate the inverter sensor within the correct time after the fuser exit switch is made, for a duplex 2 sheet.
• Remedy: NOTE: The door interlock switch must be cheated when checking +24V components. Enter dC330 code 10-100 fuser exit switch, S10-100. Press Start. Manually actuate the switch with a piece of paper. The display changes. Y↓N→Go to Flag 1. Check S10-100. Refer to: • GP 13 How to Check a Switch. •. • P/J35, IOT PWB. • 01D +3.3V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Fuser exit switch, PL 10.10 Item 11. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 sensor code 10-105 inverter sensor, Q10-105. Press Start. Use a piece of paper to actuate the sensor. The display changes. Y↓N→Go to Flag 2. Check Q10-105. Refer to: • GP 11. How to Check a Sensor. •. • P/J61, IOT PWB • 01E +5V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter sensor, PL 10.12 Item 19. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Check the following components, refer to GP 7: • The drive gear on the fuser module, PL 10.10 Item 1. • The fuser drive gear on the main drives module, PL 4.12 Item 10. • Fuser web motor and the fuser web, 10A Fuser Web Motor RAP. • Drives between inverter and the main drives module, PL 10.15. • Post fuser exit roller, PL 10.12 Item 9. NOTE: Excessive post fuser exit roll wear causes buckle between the fuser and the inverter assembly. This can cause severe ripple on the trail edge of A3 (11x17 inch) sheet and paper jams. • Upper baffle, PL 10.12 Item 22. • Baffle guide, PL 10.13 Item 3.

• Code: 10-135, 10-136, 10-137, 10-138
• Description: Trail edge Late from Inverter Sensor RAP 10-135 The trail edge of the paper failed to de-actuate the inverter sensor within the correct time, for a simplex non invert sheet. 10-136 The trail edge of the paper failed to de-actuate the inverter sensor within the correct time, for a simplex inverted sheet. 10-137 The trail edge of the paper failed to de-actuate the inverter sensor within the correct time, for a duplex sheet side 1. 10-138 The trail edge of the paper failed to de-actuate the inverter sensor within the correct time, for a duplex sheet side 2.
• Remedy: NOTE: Ensure that the door interlock switch is cheated when checking +24V components. Enter dC330 code 10-105 inverter sensor, Q10-105. Press Start. Manually actuate the sensor. The display changes. Y↓N→Go to Flag 1. Check Q10-120. Refer to: • GP 11 How to Check a Sensor. •. • P/J61, IOT PWB. • 01E +5V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter sensor, PL 10.12 Item 19. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-050 inverter nip solenoid, SOL10-050. Press Start. The solenoid energises. Y↓N→Go to Flag 2. Check SOL10-050. Refer to: • GP 12 How to Check a Solenoid or Clutch. •. • P/J5, IOT PWB. • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter nip solenoid, PL 10.11 Item 6. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-045 inverter path solenoid, SOL 10-045. Press Start. The solenoid energizes. Y↓N→Go to Flag 3. Check SOL 10-045. Refer to: • GP 12 How to Check a Solenoid or Clutch. •. • P/J5, IOT PWB • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter path solenoid, PL 10.11 Item 14. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-055 tri-roll nip split solenoid, SOL 10-055. Press Start. The solenoid energizes. Y↓N→Go to Flag 5. Check SOL 10-055. Refer to: • GP 12 How to Check a Solenoid or Clutch. •. • P/J61, IOT PWB • P/J17, LVPS. • Fuse, PL 1.10 Item 9, GP 7. • 01G +24V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Tri-roll nip split solenoid, PL 10.14 Item 1. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Enter dC330 code 10-030 inverter motor, MOT10-030. Press Start. The jam clearance knob, 2B, PL 10.15 Item 13, is stationary and the motor can be heard. Y↓N→The jam clearance knob, 2B, PL 10.15 Item 13, rotates counterclockwise. Y↓N→Go to Flag 4. Check MOT10-030. Refer to: • GP 10 How to Check a Motor. • P/J4, IOT PWB • P/J45, P/J55 • 01G +24V Distribution RAP • 01E +5V Distribution RAP. • 01B 0V Distribution RAP. Install new components as necessary: • Inverter motor, PL 10.11 Item 11. • Inverter motor driver PWB, PL 10.11 Item 22. • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. Install a new inverter motor driver PWB, PL 10.11 Item 22. Check the following components, refer to GP 7: • Idler roll, PL 10.12 Item 15. • Upper baffle, (65-90ppm) PL 10.12 Item 22, (35-55ppm) PL 10.12 Item 23. • Double exit nip rolls, PL 10.11 Item 8. • Exit shaft assembly, PL 10.13 Item 4. • Nip split shaft assembly, PL 10.11 Item 4. • The drive gear on the fuser module, PL 10.10 Item 1. • The fuser drive gear on the main drives module, PL 4.12 Item 10. If the fault still occurs, the +24V supply from the LVPS may be faulty. Install a new LVPS, PL 1.10 Item 3.

• Code: 10-315, 10-320, 10-321, 10-323, 10-340, 10-350, 10-360, 10-365, 10-380
• Description: Fuser Over Temperature RAP 10-315 The difference between 2 consecutive thermistor readings exceeds a given value. 10-320 During standby or run mode, the thermistor reading is not within the target temperature range. 10-321 Over temperature during standby mode, the thermistor reading is not within the target temperature range 10-323 Over temperature during run mode, the thermistor reading is not within the target temperature range. 10-340 Fuser temperature sensor A reading monitors above its normal operating temperature. 10-350 The hardware comparator detects a fuser reading greater than 240 degrees centigrade or a short circuit thermistor. 10-360 Fuser temperature sensor B reading is greater than the normal operating temperature. 10-365 The fuser module is above the recommended operating temperature. 10-380 The fuser delta value between the temperature sensors A and B is to high.
• Remedy: Switch off the machine, then switch on the machine, GP 14. The display shows Ready to Copy. Y↓N→Refer to. Go to Flag 1. The voltage at the temperature sensors A and B should be 2.9 volts when the sensors are cold. In standby mode the voltage should be 0.78 to 0.98 volts. Refer to: • P/J35, IOT PWB. • 01D +3.3 V Distribution RAP. • 01B 0V Distribution RAP Before new components are installed, restore the NVM values to default. Install new components as necessary: • Perform OF7 IOT PWB Diagnostics RAP before a new IOT PWB is installed, PL 1.10 Item 2. • LVPS and base module, PL 1.10 Item 3. • Fuser Module, (35-55 ppm) PL 10.8 Item 1, (65-90 ppm) PL 10.10 Item 1. Perform SCP 6 Final Actions.