This is rather a broad & trivia question:
**What would possibly cause the VERT_FILTER_LOCKED bit stay low (not locked) ?
This is the HDMI map - register 0x07 - bit - Please refer to HW Manual rev J- page 59
PS. The reason I ask this question because we were reported a case when an unknown video works fine on a unknown monitor, but when the video fed to the ADV7441A (of course on our board), the VERT_FILTER_LOCKED stay low... This happens on the field and we were reported with these info... it's impossible to duplicate what happens with the Eval board...