Member Avatar for Dontais

I recently purchased a mindvi to dvi and a converter to vga, I did some research and most sites it should work when you mirror the desktop. But what happens I pick up the projector or even tv, and it allows me to change the resolution of both displays but nothing shows on the projector or tv.

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If the Mac lists an external display (as suggested) but the projector/TV stays black (the situation described), focus on three likely causes: signal type mismatch in the adapter chain, projector/input handshake or timing, and macOS display negotiation. The following checks are practical and quick.

  • Power and input: power the projector/TV first, set it to the correct VGA input, then connect the Mac. Some projectors need to see an active input before they will display a signal.
  • Force detection and safe resolution: open System Preferences -> Displays, hold the Option key to reveal Detect Displays, click it, then choose a conservative resolution like 800x600 or 1024x768 at 60 Hz. Mirroring can fail if the chosen timing is unsupported by the projector.
  • Adapter type (most common cause): passive DVI-to-VGA adapters require the source to output analog VGA on the DVI pins. If the DVI side is digital-only (DVI-D), a passive converter will produce no picture even though macOS shows a display. The fix is to use a direct Mini-DVI/Mini-DisplayPort-to-VGA adapter or an active digital-to-analog converter that explicitly states it converts DVI-D/HDMI to VGA.
  • Isolation tests: try the adapter/cable on a known-good monitor, or try a known-good VGA cable/projector. Swap cables and adapter to narrow which link fails.
  • NVRAM/SMC reset (last resort): reset PRAM/NVRAM (hold Command+Option+P+R at boot until the second chime) and SMC (model dependent; nonremovable battery Macs use Shift+Control+Option + power) if nothing else works.

If a safe resolution shows an image, work upward until the projector’s preferred timing is found. If no image appears after these steps, the adapter chain is almost certainly incompatible and replacing it with a single, purpose-built adapter or an active converter will resolve the issue.

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Member Avatar for mesamb1

Try going into system preferances and display, check and see if it is recognizing the projector as a second screen.

Member Avatar for Dontais

It does recognize the display and allows me to change the resolution but when I set the Sanyo Dpl and he macbook nothing comes up.

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