HDMI ---No display for nano custom board

  DP1 HDMI does not display, the hot-HDP pin changes from 1.8V to 0.6V after about 7 seconds of system startup, EDID detection passes, and no image is displayed. The moment when the voltage changes seems to be the moment when the load current suddenly increases
  The system startup sequence is shown in the attachment. 1.8V has a voltage of 1V before and after the carrier board is powered on. Is this normal? Is this the module output?

XXXXX_2020-05-28_17-23-01.log (55.7 KB)


There is no software error in dmesg. It is more likely a hardware issue.

Obviously, the incorrect level of the hot-swap pin causes this problem. If the power-on meets the timing requirements, there are other reasons for this phenomenon.
In addition, I measured the voltage of the SYS_RESET pin, only 1.5V, is this normal?

Our hardware engineer will help check. Please wait for reply.

Is it your custom board or devkit? Can your board power on system successfully? Did you follow the OEM DG to make the design?


There is no update from you for a period, assuming this is not an issue any more.
Hence we are closing this topic. If need further support, please open a new one. Thanks