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Why is there no signal on my HDMI AOC after Installation?

by Stuart Berry June 03, 2020

There are a lot of HDMI Cables on the market, but they are divided into 2 styles: passive HDMI cable and active HDMI Cable. The difference between them is that passive HDMI cable has no chipsets, but the active one has chipsets inside.

Active HDMI cables are divided into Active Copper HDMI cable (Redmere solution) and Active Optical HDMI cable (Smartavlink’s solution).

It is generally accepted that Active Optical HDMI cable is the high-speed HDMI signal transmission solution of the future. This is because fibre optical versions can reliably send the highest bandwidth from a 1G to a 100Gbps signal. This solution is now being widely adopted in home theatres and meeting rooms. But on occasion we find HDMI AOC cable does not work after it has been installed? Why is that?

Before we look into this, we need to understand how the two types of cable differ.

HDMI (High-Definition Multimedia Interface)

HDMI is a proprietary audio/video interface for transferring compressed or uncompressed video and audio data from an HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device. HDMI is a digital replacement for analog video standards.

HDMI AOC (HDMI Active Optical Cable)

HDMI AOC (Active Optical Cable) is a kind of cable that replaces the copper cable, and the port can be used directionally as with copper HDMI cable. It uses Electronic-Fiber and Fiber-Electronic converting technology to send HDMI signals through fibre optical.

HDMI AOC has the following advantages:

  • Long-distance. The max distance can be 100m without any signal loss or delay.
  • High bandwidth. It ranges from 18Gbps (HDMI 2.0) to 48Gbps (HDMI 2.1).
  • Easy Installation, plug in plug out, and no need an external power supply.
  • Soft, flexible, and slim, and lower EMI interrupts.

hdmi aoc active optical cable

Why is your HDMI AOC without signal after Installation?

If you find that there is no signal after Installation, how do you troubleshoot?

Possibility One: Wrong direction.

Fibre optical HDMI cable is a uni-direction product, and the HDMI signal is sent by lighting, so you have to put Source to PC/STB/DVD and make display side connect to TV/Screen/Project, etc.

hdmi aoc cable distance

Possibility Two: The cable is broken.

Because the internal cable is optical fibre, whether plastic optical fiber or glass optical fiber, there is a bending radius, so please read your cable manual before Installation to avoid cable fracture or bending radius error. Smartavlink's HDMI AOC can knot, and its bending half diameter in the market is very small so as to avoid the risk.

cable knot

Possibility Three: Compatibilty Problem.

HDMI AOC is an active HDMI optical cable, which has a chipset. It's important to ensure that the EDID reading of the TV (display end) and DVD (source end) is successful, and then your TV will start. Before starting to use HDMI AOC, testing is very important.

Possibility Four: VCSEL.

The final possibility is that the cable does not work on any HDMI device, but the cable is not disconnected. In most cases, VCSEL crashes. If it fails, the manufacturer needs to test it in the room. The following two pictures show the VCSEL of the crash. HDMI has a total of four lanes, but from this picture, you see only three lights, which means one lane VCSEL fails.


In order to pursue low-cost marketing, many manufacturers change the internal VCSEL, adopt low-quality VCSEL, improve mold productivity, and shorten the service life, which are all high-risk defects in marketing. Smartavlink insists on using high-quality VCSEL of big brands to enhance the stability of HDMI AOC (such as II-VI, Philips) and avoid the risk of VCSEL chip.


Smartavlink launched HDMI-AOC development six years ago. They are the first generation of the HDMI-AOC development team, providing a one-stop service from the design, assembly, and testing of the HDMI engine.

Contact our Technical Sales Team here at ITM to find out more.

Stuart Berry
Stuart Berry


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