TPD4E05U06: HDMI output does not work.

Hi, 

Just a few questions, are you plugging the board into an HDMI port on both the PC and monitor? Also, have you tried removing the diodes to see if the board works? Nothing on the schematic or board jumps out at me as being incorrect.

Best,

McKenzie

Hello. 

Thank you for your reply.
Yes, I connected both the PC and the Monitor.
When you say diode, do you mean D4?
Even after removing D4, the image still does not appear.

Best Regards

Hi, 

By removing the diodes, I meant all so ESD224, TPD4E05U06, and TPD1E05U06. Would it be possible to send the board files so I can go through it?

Best,

McKenzie

Hello.

There are boards that do not have ESD Protection ICs, but they have the same symptoms.
I have one question.
I understand that there should be a gap of 1.2mm or more between TMDS lines.
The gap between the TMDS lines on the HDMI Connector side of the PC is 0.8mm. Could this be the problem?

Best Regards

Hi Sincheol,

While the gap between traces could affect the signal I'm not sure if it would completely kill the image. I would expect to at least see a corrupted image or some noise instead.

Since the board still does not work after removing the ESD diodes, this sounds like a layout or manufacturing issue. If you have access to a logic analyzer or oscilloscope, have you checked that the data is being sent properly across the board? Alternatively, have you checked continuity from connector to connector with a multimeter or similar tool? 

Best,

Chris

Hello. Chris Pui,

I checked with a multimeter, but there was nothing unusual.

I couldn't find any problems on the PCB.

It will cost money, but I plan to remake the board with a distance of 1.2mm or more between TMDS.

It doesn't seem easy to find a proper method at the moment.

Thanks.

Mr. Kang

Hello. McKenzie,

OK. I respect your opinion.
First of all, I checked that the board using a different type of connector works, so I expect it to be a problem with the spacing of the TMDS lines. I would like to ask if I can request a review after proceeding with the artwork.

Best,