DS90UB948-Q1: Why the screen has no image?

Dears:

We design the schematic as below picture:

1. There is CPU control, initiate and have a time series with DS90UB947' PDB according the errata and datasheet. 
2. DS90UB948’s PDB is pulled up with power.
3. After initiating DS90UB947, we reset DS90US948 by setting register.

From the situation, there will happen the screen has no image, however, the back lighting is ok.

Why it happen? Is it something to pay attention about it?

Thanks a lot!

Best regards

Luck Wu