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DLP4500: DLP4500 HDMI VSYNC lock

Part Number: DLP4500

I am having problem with the locking of HDMI signals. Signals are detected but Signal Status is stuck in "Processing".  The most likely cause is that both Horizontal and Vertical Resolutions are off by 1 or 2. For example, an images of 1280x800 may be detected as 1282x801.  I have tried different resolutions (1280x800, 1024x768, and 912x1140), different HDMI cables all with ethernet, different signal sources (Windows PC and Raspberry Pi), and different firmware versions (4.4 and 2.0).  The problem stayed the same.  An interesting observation is that correct resolution was shown during rebooting of Raspberry Pi, and the Signal Status changed for a short while to "Detected".  However the problem returned as soon as the computer finished rebooting.      

  • Hello Wang,

    Welcome to DLP forum and thank you for your interest in DLP technology.

    Could you please share further details like system connect and also frame details like (resolution, frame rate, pixel clock)?

    regards,

    Vivek

  • Hi Vivek,

    Thank you for the rapid response.  I think I have solved the problem, which was likely due to corrupt EDID on my LightCrafter.  I found an appropriate EDID file online for 1280x800_60Hz then applied it to Raspberry Pi using the commands of hdmi_edid_file and hdmi_edid_filename in config.txt.  The Signal Status is now "Detected". 

    It would be nice to have the original EDID file particularly for 912x1140.  Also helpful would be more detailed instructions for restoring corrupt EDID.