DS90UB954-Q1: No image output after a few minutes of work

Hi,

Thanks for reaching out with this concern. I will look through this schematic and provide feedback accordingly. 

While I review the schematic, could you please help with a few questions on the issue observed?

• Does this issue appear consistently every power cycle?
• When the "no image" issue is seen, do we have stable lock? This can be read in register 0x4D of the deserializer.
• As an experiment, it may be helpful to try using pattern generation on the serializer, or pattern generation on the deserializer to see if the generated image is stable.

Best,

Thomas

Hello,

1: Not every time you power on, there will be no video for a while, but occasionally.
2: No video appears, the register value is normal.
3: indicates the transmission pattern. There is also no pattern.

Hi,

Based on this symptom it appears that there could be a drop in lock when the issue is observed. Could you please check on the below items?

1. when the failure occurs can you read register 0x4d? Note that this is a port specific register and 0x4C must be set to select the applicable RX port
2. Could you try using patgen on the deseriailzer to see if this output is stable? pattern generation can be seen in section 7.5.11 of the UB954 datasheet

Best,

Thomas