DS90UB948-Q1: Black screen problem

Hello ian,

Black screen can have multiple reasons, such as:

- UnLOCK between SER and DES

- No Video signal at the input of the SER

- Poor quality Video signal or PCLK at the input of the SER

- Not clean power-up sequence on the SER or on the DES.

- The DES enteres AV mute state

- Cable betwen SER and DES is not connected or not correct polarity

- No or Poor signal at the input of the DES

Hi Ti engineer: 

- The DES enteres AV mute state

 How to know the DES whether to enter AV mute state? By reading register?

Hello,

It is not possible to see if the device enters AV Mute by reading registers.

But if the device is really enteres AV Mute, then there will be clock signal but no data signals at the oLDI outputs. Is this the case?

Hi：

when the screen is black, clock and data both have outputs. The device should not be AV Mute state.

Yes, If clock and data are present, then this should not be AV mute state.

Hence, please make sure of all points I listed above.