I have designed ADV7401 in two separate products and overall it works very good. ADV7401 is configured to generate 16bit YCrCb with embedded sync. Its output goes to ADV7321 as well as Gennum HD-SDI transmitter.
I have noticed a unique problem in both products and on every single board.
When I input 1080i/p video in the Component input (YUV), the video output looks great & stable. However, when I tap or vibrate the PCB, I see horizontal tear (a few lines) on the video monitor. When I stop tapping, the video is stable.
This problem does not occur with Standard Definition input (PAL or NTSC).
All the components are SMT and soldered perfectly.
How could vibration cause this problem?
Any suggestion is much appreciated.