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Zorluk: Çok zorVideo, Display, and Projector Issues

A field technician is dispatched to a corporate conference room where a newly installed ceiling-mounted projector is experiencing intermittent video degradation. The presenter's laptop is connected to the projector using a 50-foot (15-meter) passive HDMI cable run through the wall. When transmitting a 1080p video signal at 60Hz, the image displays normally. However, whenever the laptop resolution is increased to native 4K at 60Hz to display detailed engineering schematics, the projected image experiences digital noise ('sparkles'), brief black screens, and periodic loss of signal sync. Lowering the resolution back to 1080p immediately stabilizes the display. Which of the following is the most appropriate action for the technician to take to resolve this issue?

  1. Replace the passive cable with an active HDMI cable or an HDMI-over-Ethernet extender systemCevap
  2. B
    Replace the projector's backlight inverter board to supply higher voltage required for 4K decoding
  3. C
    Roll back the laptop's graphics adapter drivers to resolve video memory timing corruption during high-resolution rendering
  4. D
    Adjust the projector's optical keystone settings to compensate for signal sync loss at higher pixel clock rates

Cevap

Replace the long passive HDMI cable with an active HDMI cable or an optical/Ethernet extender system designed for long-distance 4K video transmission.
Passive HDMI cables suffer from high-frequency attenuation over long distances (typically over 15 feet). While lower-bandwidth signals like 1080p can pass successfully, higher-bandwidth signals like 4K@60Hz experience bit errors manifesting as digital sparkles, sync drops, and black screens. Resolving this requires active signal regeneration via an active HDMI cable, fiber-optic HDMI, or an HDBaseT extender.

Adım Adım Çözüm

1
Analyze the symptoms across different resolution settings
The video signal operates stably at 1080p (lower bandwidth demand: ~4.95 Gbps) but fails with signal dropped frames and digital noise at 4K@60Hz (higher bandwidth demand: ~18 Gbps).
Determines whether the issue is related to video bandwidth capacity and signal attenuation over distance.
2
Evaluate physical layer transmission constraints
Standard passive HDMI cables experience significant signal degradation (attenuation) over distances exceeding 15 feet (5 meters) when attempting to carry high-frequency 4K signals.
Long passive cable runs cannot maintain digital signal integrity for high-bandwidth HDMI specifications without active boosting.
3
Select the correct corrective hardware action
Installing an active HDMI cable (which includes embedded signal-boosting chipsets) or an HDMI over HDBaseT/Cat6 extender kit restores clean signal transmission at 4K resolution.
Provides the necessary signal amplification to overcome insertion loss across long physical distances.

Anahtar Kavram

Display Cable Bandwidth & Distance Attenuation Limits
Tahmini Süre:1m 30s
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