Using a projector with MacBook Pro

On the MacBook go to Apple Menu > System Preferences > Displays

set the resolution for the projector to 1024 x 768

Use the "Thunderbolt" to VGA adapter, if its not an Apple product expect problems, so buy the Apple adapter from Amazon or Ebay as Apple no longer sell it

to get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display. "No signal detected" is generated by the DISPLAY, not by the Mac.

This query is only sent at certain times:

• at startup

• at wake from sleep — so momentarily sleeping and waking your Mac may work

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• on invoking Option-(Detect Display) button in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

Modern Displays with multiple ports are sometimes busy scanning the other ports, looking for an input, and miss the query from the Mac. They need to pay attention to the port you are actually using, or they will miss the query.

Some displays have On-Screen Display settings that can be used to tell the display a computer is attached on a certain port, or a certain port should be highest priority. Changing those may make your display more responsive.

Some displays include their own private "sleep" settings for the display alone. This can allow the display to enter its own sleep mode, on top of the Mac's not sending it data. A display that is sleeping on its own cannot respond to the Mac's query, and will stay dark.

On a PC, it uses whatever settings you manually make in its preferences, and pays no attention to what (if anything) the display says about its capabilities).

ThunderBolt-to-HDMI is more likely to succeed, and from that vendor, a good quality adapter costs under US$10. Others may be available from other sources, and should be priced comparably.

it is probably a mistake to attempt to convert HDMI to anything else.

Lots of vendors sell USB-C to VGA adapters.

Apple's version also has a charge port and a USB-A data port, but costs US$70.

If your Mac has only ThunderBolt-2 ports, the adapter is even cheaper:

Monoprice Mini DisplayPort 1.2a / Thunderbolt to VGA Active Adapter, White - Product # 12785 -$5.71  

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