Sometimes a UV printer works normally across most of the print area, but the ink output becomes abnormal at one specific position.
For example, you print a large image and notice a missing or broken section near the right side. You change the artwork, but the new image develops a similar problem in the same area.
When this happens, the cause may be the image file, encoder strip, or carriage board.
What Does This Problem Look Like?
You may notice:
- Missing ink in one area
- Broken lines at a certain position
- Colors dropping out in the same location
- Part of the image printing incorrectly
- Different files showing the same defect in the same area
The location of the problem gives you an important clue.
Test With a Different Image
Load another image and print it in the same area.
If the new image prints normally, the original file may be the problem.
The artwork may not have been processed correctly by the RIP software.
In this case, delete the old print job. Reload the original image and process it again in the RIP.
You can also test with a simple image that has printed correctly before.
Move the Image to Another Position
This is one of the easiest ways to narrow down the cause.
For example, imagine a logo prints badly at the center of the bed.
Move the same logo to the left side and print it again.
If the problem moves with the image, check the file or RIP processing.
If the logo prints correctly on the left but fails again when placed in the center, the problem is more likely related to the printer hardware.
Check the Encoder Strip
The encoder strip helps the printer know the exact carriage position.
Dust, ink mist, scratches, or damage on the strip can make the carriage read the wrong position.
This may cause ink to fire incorrectly at a certain point.
Inspect the encoder strip carefully.
Look for:
- Ink stains
- Dust
- Scratches
- Loose mounting
- Physical damage
If it is dirty, clean it using the method recommended by the printer manufacturer.
Do not use strong chemicals unless they are approved for the strip.
If cleaning does not help and the strip is damaged, replacement may be needed.
Check the Carriage Board
If different images still show abnormal ink output in a certain area, the carriage board may also be involved.
A carriage board fault can affect how firing signals are sent while the carriage moves.
You may see:
- Ink dropout at a certain position
- Random firing in one area
- A problem that appears only during part of the carriage travel
If possible, test with a known-good carriage board.
Replace only one part at a time. This makes it easier to find the real cause.
A Simple Way to Narrow It Down
A useful Printer Troubleshooting test is:
- Print a different image in the same position
- Move the original image to another position
- Compare the results
- Inspect and clean the encoder strip
- Test the carriage board if the problem remains
If the problem follows the image, check the file.
If every image fails in the same physical area, check the encoder strip.
If the issue appears only during a certain part of carriage movement and the strip looks normal, the carriage board may need attention.
This type of test can save a lot of time because you are using the position of the defect to find the cause instead of replacing parts at random.