Como identificar e reparar defeitos em displays industriais?

Dead or Stuck Pixels: Why You See Dots That Don’t Disappear

One of the most recognizable display issues is the appearance of small, static dots—black or bright red, green, or blue—that don’t respond to changes on the screen.

What’s Happening?

These are typically dead pixels (black and non-functional) or stuck pixels (fixed on a single color). They occur due to:

• Tiny electrical failures in the pixel circuit (factory defect)
• Pressure or physical damage during handling or operation
• Long-term display of static images causing pixel burn-in or freeze

How to Fix It

• Run pixel refresh software that cycles colors rapidly—sometimes this “shocks” stuck pixels back to life
• Display fast-moving video or color loops for several hours
• If the pixel remains unchanged and the screen has visible pressure marks, consider panel replacement

How to Prevent It

• Avoid pressing on the display surface
• Use protective casing or bezels in rugged environments
• Rotate content on-screen regularly to prevent image retention

Flickering Screens: When the Display Won’t Stay Still

Flickering or blinking makes it difficult to read process data or interact with the HMI. This issue is especially common in factory floors where power supply quality may fluctuate.

Likely Causes

• Power instability (voltage drops or spikes)
• Faulty cables or poor-quality shielding
• Mismatched refresh rates between the monitor and system
• Outdated or incompatible display drivers

What You Can Do

• Check the Power Supply: Ensure that your monitor is connected to a stable power source. Using a surge protector can help stabilize the voltage.
• Inspect Cables: Loose or poor-quality cables can cause issues. Replacing them with high-quality, shielded cables can improve the situation.
• Adjust Refresh Rate: Make sure the refresh rate of your monitor matches your system’s settings. Check your monitor’s manual for the recommended settings.
• Update Drivers: Keep your graphics drivers up to date to avoid compatibility issues.

Long-Term Fix

Implement preventive maintenance routines that include cable inspection, firmware updates, and environmental checks for EMI sources.

• Using good-quality cables and ensuring a stable power supply can minimize flickering.
• Regularly update drivers and perform general maintenance checks to avoid these issues in the future.

Blurry or Low-Resolution Display: When Text Isn’t Clear

When you’re trying to read important data, the screen looks blurry or pixelated. Images or text might not be as sharp as they should be, even when you’re not zooming in or out.

If text or icons look fuzzy even when zoomed to normal size, this usually signals a mismatch between the panel’s native resolution and the system’s output.

What Causes It

• Display is set to non-native resolution
• Internal misalignment from shock or vibration
• Loose connections in internal wiring or controller boards

Solutions

• Adjust settings to match the display’s native resolution
• Secure display components in high-vibration environments
• Inspect and re-seat internal flat cables or connector pins

Prevention Tips:

• Use monitors specifically designed to handle vibrations or shocks if working in environments where these are prevalent.
• Always use the monitor’s native resolution to maintain image clarity.

Best Practices

In industrial setups with heavy equipment nearby, use displays certified for shock and vibration resistance, and mount them with anti-vibration brackets.

Backlight Failure: Why Is My Screen Going Dim?

A sudden loss of brightness or a black screen often points to backlight issues—one of the more common failures in aging displays.

What It Looks Like: The screen suddenly becomes very dim or goes completely black, making it impossible to see anything. This usually happens when the backlight of the display fails.

Key Triggers

• CCFL or LED backlight degradation due to age
• Inverter or driver board failure
• Power instability affecting the backlight circuit

How to Identify

• Hold a flashlight to the screen—if the image is faint but present, the backlight is the issue
• Test backlight voltage output or replace the driver board

Recommended Fixes

• Upgrade CCFL displays to LED backlight models
• Replace backlight components or panels with known failure rates
• Avoid running at 100% brightness unless absolutely necessary

Touchscreen Not Responding: When Input Goes Unregistered

In HMI terminals, unresponsive touchscreens can halt operations. This is especially critical when screens serve as the main control interface.

What It Looks Like: You tap the screen, but it doesn’t respond, or it behaves erratically, registering touches incorrectly or in the wrong locations.

Common Causes

• Surface damage (cracks, chips, scratches)
• Faulty or degraded touch sensor
• Environmental interference (moisture, dust, temperature)

How to Resolve

• Clean the surface with a soft, lint-free cloth and alcohol
• Recalibrate using the system’s built-in tools
• For resistive screens, check wiring; for capacitive, check grounding and controller board

Smart Prevention

• Use industrial touchscreens with IP-rated protection
• Add anti-glare tempered overlays
• Choose capacitive panels with glove support tuning for field use

Color Distortion: When the Display Looks Too Blue, Yellow, or Washed Out

Color accuracy is critical in applications like medical diagnostics ou graphical process monitoring. Color shifts can compromise performance or even lead to incorrect data interpretation.

What It Looks Like: The colors on your screen appear distorted—either too bright, too dull, or with a noticeable tint. This can cause problems if accurate color display is important for your work.

Root Causes

• Aging LEDs or CCFLs affecting color balance
• Uncalibrated settings after driver updates
• UV exposure or extreme heat deforming the liquid crystals

How to Troubleshoot:

• Calibrate the Screen: Use color calibration tools to ensure the display is showing colors correctly.
• Check for Environmental Effects: Ensure the screen isn’t exposed to extreme temperatures or sunlight, which can distort colors.
• Inspect the Backlight: Check if the backlight is functioning properly, as issues here can lead to poor color accuracy.

Fixes

• Perform color calibration using ICC profiles or onboard tools
• Inspect for uniformity issues or LED wear
• Move the display away from sunlight or excessive heat

Final Thoughts: Building for Durability from the Start

Many issues like Danos por pontos no LCD ou cintilação podem ser atribuídos a decisões de projeto — não apenas ao envelhecimento ou acidentes.

Em Ecrã RJY, ajudamos OEMs e integradores de sistemas a criar displays robustos otimizados para ambientes severos. Desde ligação ótica e módulos de backlight personalizados para painéis de toque compatíveis com luvas, nossas soluções personalizadas de LCD são construídas para suportar as realidades da implantação industrial.

FAQ

O que causa danos por pontos no LCD em telas industriais?
Danos por pontos no LCD geralmente resultam de pixels presos ou mortos, que podem ser causados por defeitos de fabricação, imagens estáticas prolongadas ou pressão física. Em ambientes robustos, vibração excessiva ou impacto também podem danificar a camada de cristal líquido.

Pixels presos podem ser reparados?
Em alguns casos, sim. Executar software de renovação de pixels ou exibir padrões de cores de mudança rápida às vezes pode desprender pixels. No entanto, se o ponto for causado por falha de hardware, a substituição do painel pode ser necessária.

Por que minha tela industrial está cintilando intermitentemente?
A cintilação está comumente associada a instabilidade de energia, interferência de sinal ou uma incompatibilidade entre a taxa de atualização do seu dispositivo e a taxa nativa do monitor. Usar cabos blindados de alta qualidade e fontes de energia estáveis geralmente resolve o problema.

Como evito falhas da tela de toque em ambientes severos?
Use telas de toque classificadas para IP65 ou superior, aplique películas protetoras antirreflexoe escolha telas capacitivas ajustadas para entrada com luva ou umidade. A calibração periódica também garante precisão duradoura.

O que devo fazer se minha tela escurecer ou ficar preta subitamente?
Isso provavelmente indica falha do backlight. Verifique a fonte de alimentação e o circuito driver do LED. Para modelos antigos com backlights CCFL, considere atualizar para LED para maior longevidade.

Posso recalibrar uma tela de toque que está respondendo com imprecisão?
Sim. A maioria dos sistemas industriais inclui uma ferramenta de calibração ou opção de menu. A calibração alinha a entrada de toque com as coordenadas visuais e deve ser realizada regularmente, especialmente após a instalação ou atualizações do sistema.

Recursos de referência

• Como Corrigir Pixels Presos – TechSpot
• Guia de Manutenção de Display Industrial – Advantech