Four ways to Troubleshoot HDMI Video systems with QuantumData 780 test instrument

special thanks to Tom Schulte, SpectraCal business development manager, for the source information on how to Troubleshoot HDMI Video systems.

The background situation - on how to Troubleshoot HDMI Video

Video system troubleshooting has become much more challenging with feature-laden HDMI systems than it ever was with analog video systems. To quickly Troubleshoot HDMI Video systems, you need the right knowledge and equipment.

HDMI cable payload is much more complex, as it is probably carrying video signals and multichannel audtio signals, as well as auxiliary channel EDID data, HDCP content protection handshaking, audio and video infoframe data, CEC data, and hot plug signaling data.

The HDMI signal may be routed through cable extenders, splitters, an A/V receiver and a video processor on it's way to the display.

3D HDMI Content

HDMI cable may now also be carrying 3D video and 3D EDID Vendor Specific Infoframe data. This data informs the display device that the video signal is 3D and the type of 3D format.

Cable & satellite providers will likely send squeezed side-by-side left eye & right eye images at 1080i30. Each image contains half normal horizontal resolution. This 3D format is know as Side-by-Side (Half).

Local broadcast station providers are apt to transmit squeezed top & bottom, left eye & right eye images at 720p60 or 1090p24. Each image contains half normal vertical resolution. This 3D format is know as Top and Bottom.

Blu-ray discs will contain full resolution top & bottom 1920x1080 left eye & right eye images, both packed into a single expanded 1920x2205 frame at a 24Hz frame rate, with a horizontal 45 pixel center blanking bar. This HDMI 1.4a 3D format is know as Frame Packing.

3D source devices are required to provide at least one of the 'mandatory' HDMI 1.4a 3D delivery formats. 3D-compatible display devices are required to support all of them. 3D repeaters, between the source and display devices, need to be capable of passing 3D video images & 3D Infoframe data.

3D TVs convert whatever signal they receive into sequential left eye/right eye image for viewing with active shutter glasses. Only the physical resolution and frame rate of the displayed images will vary.

When 3D images aren't properly displayed, how do you Troubleshoot HDMI Video system? You can substitute cables and components or you can quickly resolve the problem with a QuantumData 780 handheld test instrument.

4 Troubleshooting Steps - to isolate the HDMI problem and identify the reason that images aren't being displayed properly

1. Emulate a source device with 780 to test the video display (sink device)
2. Emulate a source device to test the signal delivery path
3. Emulate both source & sink devices with 780 to test each of the components in the signal delivery path
4. Emulate a sink device to test the source device


Troubleshoot HDMI Video with QuantumData instruments