If there is a HDMI signal connected (HDMI Present LED is ON) to your CHD18x2 and there is no output signal on the SDI output, please check the following things:

#1 HDMI signals are often transmitted in 3G formats e.g. 1080p50, 1080p59. The CHD18x2 will output the

same or nearest format which is connected to the HDMI input. In case of a 1080p50 HDMI input signal,

the output signal will be also a 1080p50 3G-SDI.

Please make sure that the SDI equipment (SDI monitor, ...) connected to the CHD18x2 SDI output supports

a 3G-SDI signal. If not, please force the SDI output to a HD-SDI standard:


In addition or alternatively you can limit the EDID list of video standards (to SD / HD only) in the yelloGUI Video-TAB.

yelloGUI: http://support.lynx-technik.com/support/solutions/articles/1000037803-yellogui-information-and-quick-start

#2 Please make sure that the connected HDMI signal has no HDCP protected video content.