DVI转VGA正常，PC经DVI转HDMI连Exelvan投影仪无信号求助

Hey there! Let's work through this projector problem—since you're focused on audio, I'll keep this straightforward and skip overly dense video jargon.

Possible Causes & Fixes #

• Check Resolution/Refresh Rate Compatibility
  Budget projectors often have limited HDMI signal support (e.g., only up to 1080p@30Hz or 720p). Your Raspberry Pi likely outputs a signal the projector natively understands, but your PC's GPU might default to higher specs that the projector can't handle.

  • Use the xrandr command in Linux to test lower settings:
    1. First, list available outputs and modes with: xrandr --query (look for your HDMI interface name, e.g., HDMI-1)
    2. Force a lower resolution/refresh rate, like 1280x720@30Hz: xrandr --output HDMI-1 --mode 1280x720 --rate 30
  • If you prefer a GUI, head to your system's display settings and manually lower the resolution/refresh rate, testing each option until the projector recognizes the signal.

• Verify HDMI Cable & Interface Health
  Cheap or long HDMI cables can cause signal loss, and some budget projectors struggle with HDMI 2.0 signals even if they're supposed to be backward compatible.

  • Try a shorter, high-quality HDMI cable (1.5m or less) to reduce signal attenuation.
  • Clean both the PC's HDMI port and the projector's HDMI port with a soft brush or compressed air—dust buildup can cause connection issues.

• Update NVIDIA Graphics Drivers (for Zotac ZT 60404)
  The Zotac ZT 60404 uses an NVIDIA GPU, and open-source Nouveau drivers (default in most Linux distros) sometimes have compatibility gaps with budget display devices.

  • On Ubuntu/Debian: Open "Software & Updates" → go to the "Additional Drivers" tab → select the latest proprietary NVIDIA driver, install it, and reboot.
  • After installing, open the NVIDIA Control Panel and manually set the output resolution/refresh rate to match what your projector supports.

• Confirm Projector Input Source
  Double-check that your projector is set to the correct HDMI input (some models have multiple HDMI ports). Use the projector's remote or on-menu controls to switch to the HDMI input you're using for your PC.

内容的提问来源于stack exchange，提问作者Michael Irving