HDMI is designed to make interconnecting video and audio components easy by using a single cable that carries both video and audio signals. However, HDMI also incorporates anti-piracy copy protection, called HDCP (High-bandwidth Digital Content Protection), which is required by most of the content providers for the digital transfer of the highest-resolution 1080p digital video (and high-resolution audio like Dolby TrueHD and DTS-HD Master Audio) from the source device to the playback device. To accomplish this, each device has to be HDCP-compliant so they can communicate with each other. Part of this communication is what is called an “HDMI handshake”, which is the process of each device recognizing each other and determining that they are both authorized to transport this high quality digital signal. This process is repeated constantly while the digital signal is being sent over the HDMI connection. If for some reason the HDMI handshake is not successful, the signals are blocked and the video or audio stops until the HDMI handshake is successful. Occasional issues like this are common. But, if this is happening on a very regular or consistent basis, there are several things that can be tried to solve the handshake issues:
- Check all the HDMI connections. HDMI connectors can come loose easier than other video and audio connectors, so making sure they are all tight is the first step.
- Make sure high quality HDMI cables are being used, especially for longer cable runs (longer than 4 or 5 feet).
- Make sure all your devices are compatible with the latest version of the HDMI standard. Communications between devices using different HDMI standards can cause handshake issues.
- Power cycle all your equipment. This will force every piece of equipment to re-establish communications with each other, which may be all that is needed.
- Change the order in which you turn on your equipment. For instance, if you always turn on your TV first, then your home theater receiver, and then the set top box, reverse the order.
- Check the video resolution output setting on the source device. If it is set to AUTO, resetting it to the native resolution of your TV set can sometimes clear up handshake issues.
- Simplify your setup. Using HDMI switchers and long cables can add to handshake issues.