Hi team,
The customer is using TFP401A. The schematic is in the attachment.
There are two videos, video 1 and video 2 in the attachment. The video 1 is fine and normal. The video 2 is bad and abnormal.
1. In the normal of the video 1, when the customer unplugs the HDMI cable, the screen is black. And when the HDMI cable is not connected
to the board, the screen is also black. We call this board the board 1.
2. In the abnormal of the video 2, when the customer unplugs the HDMI cable, the screen is white. And when the HDMI cable is not connected
to the board, the screen is also white. We call this board the board 2.
3. Then the customer does a test. He tests the 44 pin ODCK. On the board 1, the ODCK pin can output the PWM.
But on the board 2, the ODCK pin cannot output the PWM. The TFP401A device are two batches for the two boards.
The customer does another test. He change the TFP401A device for the two boards. Then the board 1 occurs the same issue and
the board 2 is fine.
The customer has verified that the HDMI cable, the screen and other devices are fine.
Q1: Would you help me to check if the schematic is correct?
Q2: For the customer's issue, I think maybe the TFP401A device itself exists the problem. How to you think?
Best Wishes,
Mickey Zhang
Asia Customer Support Center
Texas Instruments