DS90UH948-Q1: Questions about DS90UH948-Q1 output image showing noise point issue

Hi Jacky,

• Does this happen on a single 948 IC ?
• What is the failure rate ? How many systems build and how many are failing ?
• Does this occur every power-up or what is the failure occurrence rate?
• Do you have a register dump of a good run vs. a bad run ?
• Have you tried doing ABA swap to the 948?

Jacky Wang(QD) said:

They have checked there is no issue for UH949 side when connected to other panels

Was the other panel also a 948 from this same exact system but a known good display?

Regards,
Fadi A.

Hi Fadi,

Please refer to below feedback, we also attached customer's schematic, please help to double check if any issues.

• Does this happen on a single 948 IC ? - No, currently it happened on customer's all building boards for this project.
• What is the failure rate ? How many systems build and how many are failing ? - 50pcs prototype boards build and all boards have such issue.
• Does this occur every power-up or what is the failure occurrence rate? - As long as the video signal input, it will show such issue.
• Do you have a register dump of a good run vs. a bad run ? - Customer used the default UH948 register setting, no external MCU I2C configuration involved.
• Have you tried doing ABA swap to the 948? - Yes, as all boards have such issue.

DS90UH948-Q1_Customer Schematic_5-25-2023.pdf

Thanks.

Hey Jacky,

There are a couple of things we can try here.

1. You can run patgen testing from the Des side - Rule out Des to display connection 
2. You can run patgen testing from the Ser side - Rule out Ser -> link -> Des connection (if no issue, then the problem is from the input side)
3. Try changing the LVDS format through Mapsel (Could be a color formatting issue) 

Seems like your mode_sel0 is set to mode#4 which sets map_sel = 1. 

You can change map_sel through Mode_Sel0 strap or through register.

Regards,
Fadi A.