What are the common issues of LCD segment displays and what causes them?

What are the common issues of LCD segment displays and what causes them? Below are some common problems, their possible causes, and troubleshooting methods:

I. Abnormal Display Content

• Internal Contamination:
  • Phenomenon: Small black spots, stains, chemical fibers, etc., inside the LCD screen.
  • Cause: Impurities or fibers that may have entered during production.
• Internal Scratches:
  • Phenomenon: Black or white lines appear inside the LCD screen, with PI (polyimide) scratches.
  • Cause: Physical scratches during production or transportation.
• Uneven Color:
  • Phenomenon: Inconsistent LCD screen colors, with rainbow or color stripes.
  • Cause: May be due to improper handling of PI or flattening, or uneven application of construction paint during the composite polarizing film process.
• Incorrect Background Color:
  • Phenomenon: The overall color of the LCD screen differs significantly from expectations or samples.
  • Cause: Batch differences or unstable production processes.

II. Physical Damage

• Screen Damage:
  • Phenomenon: Damaged parts of the LCD screen, including corner cracks, edge cracks, and conductive layer damage.
  • Cause: Impact, compression during transportation, or improper use.
• Poor Laminated Glass Cutting:
  • Phenomenon: Y-axis cutting or X-axis chipping results in bulges or depressions on part of the screen.
  • Cause: Cutting process issues, such as off-center cutting, over-cutting, or under-cutting.
• LCD Pin Scratches:
  • Phenomenon: Scratches on the pins on the side of the LCD screen where the PINs exit, leading to short circuits or poor conductivity.
  • Cause: Improper handling during transportation, maintenance, or installation.

III. Other Common Problems

• Polarizer Issues:
  • Scratches and Punctures: Mirror blurring, possibly caused by hard objects such as blades.
  • Watermarks: Stripes on the polarizer, possibly due to alcohol or acetone infiltration during cleaning.
  • Bubbles: Small bubbles in the polarizer on the LCD surface after lamination.
  • Incorrect Attachment: The polarizer is attached in the wrong position, such as attaching the bottom piece to the top.
• No Protective Film:
  • Phenomenon: The protective film on the surface of the polarizer is torn off.
  • Cause: Misoperation during maintenance or protective film detachment.
• Material Mixing:
  • Phenomenon: Mixing of different types and performance products, such as different versions or model specifications.
  • Cause: Poor production management leading to product confusion.

IV. Debugging and Troubleshooting

When encountering LCD segment display failures, follow these steps for debugging and troubleshooting:

• Inspect Hardware:
  • Check the LCD screen for physical damage, such as cracks or scratches.
  • Verify that pin connections are good and free from shorts or opens.
• Check Power and Circuitry:
  • Ensure stable power supply with no voltage fluctuations.
  • Check for correct circuit connections, free from false soldering, shorts, etc.
• Review Programs and Configurations:
  • Verify that the program configuration is correct and ensure all necessary initializations are complete.
  • Check that LCD-related configuration parameters are set correctly.
• Use Professional Tools for Testing:
  • Utilize oscilloscopes, multimeters, and other tools to test voltage, current, and other parameters in the circuit.
  • Use professional LCD testing software to detect the display performance of the LCD screen.
• Contact Supplier or Technical Support:
  • If the problem cannot be solved independently, contact the LCD supplier or technical support team for assistance.

In summary, LCD segment display failures may involve various issues, requiring careful troubleshooting and debugging based on specific circumstances.