Applicable Systems
Lithrone G40
Symptoms
The press console displays E-502, indicating a dampening solution flow fault. The dampening solution flow sensor has detected insufficient flow to one or more dampening units, which can cause ink-water balance issues and print quality problems.
Possible Causes
- Dampening solution filter clogged with paper lint or contaminants
- Dampening solution pump not operating or flow restricted
- Dampening solution level low in the central reservoir
- Flow sensor malfunction or calibration drift
Troubleshooting Steps
- Step 1: Check and replace the dampening solution filter if clogged
Replace filter element per maintenance schedule or when pressure drop is high - Step 2: Verify the dampening solution pump is operating and check flow rate
Clean pump intake screen and verify discharge pressure - Step 3: Check the dampening solution level in the central reservoir
Refill with properly mixed dampening solution to the correct level - Step 4: Inspect the flow sensor for contamination and verify calibration
Clean sensor and run calibration test per manufacturer procedure
How to Reset
To reset E-502: 1) Resolve the flow issue. 2) On the console, acknowledge the alarm. 3) Press Reset. 4) The press verifies dampening flow. 5) Normal printing resumes if flow is within specification.
Common Replacement Parts
- KM-G40-100: Dampening solution filter element, 10 micron (Replace monthly or when flow is restricted)
- KM-G40-105: Dampening solution circulation pump, magnetic (Clean impeller quarterly, verify flow rate)
- KM-G40-110: Flow sensor, electromagnetic type (Calibrate annually against reference)
Frequently Asked Questions
- Q: How do I maintain the dampening system?
Replace the solution filter monthly, clean the pump intake screen quarterly, check solution conductivity and pH daily, and maintain proper solution level. Use only manufacturer-approved dampening solution additives and never mix different brands or types.
- Q: What is the correct dampening solution pH and conductivity?
Standard fountain solution should have a pH of 3.8-4.5 and conductivity of 1200-1800 microS/cm (at 20C). Always verify with the ink manufacturer recommendation, as different ink formulations may require adjusted dampening solution parameters.
Source: Komori Lithrone G40 Press Manual, Edition 2020
Category: Printing