TFP401A: Display distortion when transfer from HDMI to RGB

James Zhan

Part Number: TFP401A
Other Parts Discussed in Thread: TFP401

Hi team,

My customer is using TFP401A for the HDMI to RGB, which have some distortion issue. Could you please help to check this?

When he start up the system, the display is still clear but the color is slightly red. After a while, the display has some distortion, the frequency of pixel clock raised from 30MHz to 60MHz, and it was still on with a blurred screen. The screen has mottled spots and bright color lines.

The distortion happened when he tried to display multi-color picture. If they do the black-white, it would be only a little bit color difference.

The circuit include HDMI interface, EEPROM, TFP401, 7` display.

Please check the board at attachment.

over 6 years ago

0 Ikechukwu Anyiam over 6 years ago

TI__Mastermind 35130 points

Hi James,

Does the HDMI stream include audio? It's strange that the frequency jumps like that. Can you share the schematic of the board with me at i-anyiam@ti.com?

Regards,
I.K.

0 user5926996 over 6 years ago in reply to Ikechukwu Anyiam

Prodigy 160 points

Hi Anyiam.

I am the customer who ask the question.thanks you for your answer ,but I am sorry that I can not provide the schematic because of the Company Regulations.this PCB is designed for image display, not included audio.Fortunately, the using Method of TFP401A is not very complex so you can infer the schematic by the board. the HDMI signal get in TFP4001A form the left of the board , then RGB signal was outputed in the right FPC connector。the chip below the HDMI connector is 24C02 where the EDID message is stored .Can you help me find out the reason why it work failed?

0 Ikechukwu Anyiam over 6 years ago in reply to user5926996

TI__Mastermind 35130 points

Hi Yafei,

I can't really infer much from just a picture of the board. I would need the schematic to ensure pins are connected correctly. And I don't need the entire schematic, just the part relevant to the TFP401A.

Also, it looks like the board has been extensively worked on. I can see quite a few bad solder jobs. Do you have another, cleaner board that you can try?

Additionally, what resolution is this display?

Regards,
I.K.

0 Ikechukwu Anyiam over 6 years ago in reply to Ikechukwu Anyiam

TI__Mastermind 35130 points

Closing thread as this issue is being handled over email.

0 user5926996 over 6 years ago in reply to Ikechukwu Anyiam

Prodigy 160 points

OK,thanks. I ‘ll reply to you when I prepared again.

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TFP401A: Display distortion when transfer from HDMI to RGB