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7612 not detecting a source device

Question asked by reshmi on Dec 16, 2016
Latest reply on Dec 23, 2016 by JeyasudhaMuthuPerumal

Our custom board has 7612 as a the HDMI receiver. We use ADV repeater s/w to control the chips (there is an onboard 7511 as wel). When HDMI Rx is plugged into a certain STB's HDMI output, we don't detect a lock. No 5V detected, no TMDS clock detected, hence no other audio and video params received as well. 


Some points that may be of interest:

- I probed the pins when the 2 HDMI interfaces (STB's output and our HDMI in) are connected and 5V is present.

- HSYNC and VSYNC polarities are negative when checked on an analyzer.

- This STB's signal works just fine on the eval board. The software works fine and it is able to detect the signal. 


I understand that when the 5v line is detected (or is it the TMDS clock), the HDMI rx chip needs  to enable its EDID EEPROM section and assert the HPD line high. Is that right? I dont see this part happening on our board. 


Any pointers would be really appreciated!