CompTIA Tech+ (FC0-U71)IT Concepts and TerminologyHard
A user reports that their new 4K monitor displays only a black screen when connected to their laptop, which previously worked with a 1080p monitor. The laptop's specifications indicate it supports HDMI 1.4. What is the MOST likely reason for the black screen?
- AThe monitor's refresh rate is incompatible with the laptop's GPU.
- BThe HDMI cable is not rated for 4K resolution at the required bandwidth.
- CThe monitor's input source is not correctly selected, defaulting to an unused port.
- DThe laptop's HDMI 1.4 port does not support 4K resolution at 60Hz.
Show answer & explanationAnswer & explanation
Correct answer: D. The laptop's HDMI 1.4 port does not support 4K resolution at 60Hz.
HDMI 1.4 supports 4K resolution, but only at a maximum of 30Hz. A 4K monitor typically expects 60Hz for a smooth experience. While a 4K cable (HDMI 2.0 or higher) is ideal, an HDMI 1.4 port itself cannot transmit 4K at 60Hz, leading to a black screen if the monitor expects that refresh rate.
Why the other options are wrong
- A. While possible, the primary limitation for 4K at 60Hz is often the port version, not just the GPU's refresh rate capability itself, especially if the GPU is otherwise capable of 4K.
- B. A non-4K rated cable could cause issues, but the port itself being HDMI 1.4 is a more fundamental limitation for 4K@60Hz. Even with a good cable, the port can't transmit the data.
- C. This is a common issue but less likely to be the *most* likely reason when a specific resolution/refresh rate incompatibility is present with a known port version.
HDMI Versions and Capabilities
Different versions of the High-Definition Multimedia Interface standard offer varying bandwidths, supporting different resolutions, refresh rates, and features.
- HDMI 1.4: Max 4K@30Hz, Ethernet, Audio Return Channel.
- HDMI 2.0: Max 4K@60Hz, HDR, increased bandwidth.
- HDMI 2.1: Max 8K@60Hz/4K@120Hz, dynamic HDR, Variable Refresh Rate (VRR).
Memory trick: Cables and Connectors: Check Your Specs!