TFP401A: Failure analysis results question

Hey Mark,

Are you able to provide more context on the failure on your side?

This unit was flagged at the automatic tester, so bench verification was bypassed as damage was already found. How did you determine that the damage was related to the HDMI/ DVI inputs?

The failure mode (of our product) is there no image on the LCD. We trace it back to SCDT output of the TFP401A never going 'true'.

Upon analyzing the HDMI signals incoming to the TFP401A  - comparing them side by side with a working unit (with exact same source) - the failed unit has degraded HDMI signal levels - i.e. either non-existent, or severely diminished.

We replace ONLY the TFP401A and the unit becomes fully functional and passes all QC testing.

Hey Mark,

I agree, it seems had more than just pins 55 and 66 are damaged based off of the information provided. However, the ATE saw pins 55 and 66 failed electrical testing at the ATE so they were assumed to be the root cause of the issue, as no other pins failed.

I cannot go into detail on how our package and die are connected and as this may violate a potential NDA, but ESD or IOS damage on a pin can propagate through the entire device leading to unpredictable behavior.

Is there anything specific you're looking for from us? 

Yes... we were hoping you could tell us if/which pin(s) on the HDMI input side of the TFP401A were damaged so that we could feed this back to our customer.

Are we to assume the ATE found NO failures/damage on the HDMI input pins?

Hey Mark,

Contacting the relevant engineers and managers. I will get back to you as soon as they have an update.

Where is this report?

It can be found on the QEM portal, same place you found the original report.

I was not involved with the original report - I was brought in when it was suggested we go through the E2E support forum for follow-up. 

I do not have any access or knowledge of the 'QEM portal'.

Ah understood let me send it over to you.