Configuring Second Monitor

I have always used two monitors with my PC Laptop. I'm trying to figure that out on the new MacBook pro. I went out and bought a HDMI to VGA dongle. Plugged that in. The 2nd monitor goes black (when disconnected it shows a Samsung message), so I'm pretty sure it's connected. But when it's plugged mouse clicks stop working on the built-in retina display, unplugging VGA dongle makes mouse clicks work again on the primary display. I think I'm supposed to click on system preferences / displays and do something with settings there, but it really doesn't show much other than the built in retina settings. And of course I can't get to that screen at all if the VGA is plugged in.

Does your trackpad work with the second monitor plugged in? It might be better to set this up with your mouse unplugged and use only built in hardware until it's working.

What is supposed to happen is this. Plug in and switch on the external monitor, then open System Preferences/Displays. From there, on the built in monitor, you select the second display and choose whether to extend your desktop or mirror it.

Unfortunately, I'm away from my system right now so I can't work through this with you, and memory doesn't work too well for things I rarely change.

Took your advice and I've unplugged the mouse. The trackpad cursor moves with the second monitor plugged in, but neither clicks nor other mouse events respond. So it's impossible to get to the System Preferences/Displays menu when the second monitor is plugged in. Could the monitor be incompatible with Apple? It's a fairly old, lower rez monitor, which is why I like it. Fonts look bigger on it

As for your description of what is supposed to happen, I would have guessed something along those lines.

DThompson55 said:

It's a fairly old, lower rez monitor, which is why I like it. Fonts look bigger on it.

Click to expand...

Please tell me this isn't like a 15-20 year old (or older) 14", 15", or even 17" CRT based display with a VGA port...being used with a 2015 or 2016 Apple computer?? If so...there very well could be compatibility issues.

Yes...fonts may look bigger on it...but that's because of the super low resolution. Everything else looks bigger too (not much screen real estate). If you need fonts to be larger...there are ways of doing this with settings within the Mac OS.

Do yourself a BIG favor. Get a nice inexpensive flat panel external display that's at least 22"-24". These can be purchased pretty cheaply used on Craig's List or eBay. You'll probably get way more screen real-estate on a single display like this...than both of your former 2 VGA display's combined.

Again...you could be facing some compatibility issues. Usually using an external display with an Apple computer is "plug & play". If you're running into issues...it could be compatibility.

- Nick

My guess is that HDMI to VGA is not a good mix. If you have access to a television with HDMI, try plugging into that. Video cables are much happier when they have the same connector at both ends.

Once you've tried it out on a TV and know that it works, you'll be assured that a monitor will also work with the same connection.

As Nick said, you can adjust the size of items on the display and have a much better picture.

I had to reset SMC, https://support.apple.com/en-us/HT201295, on my 2011 MBP to get the adapter/cable to work correctly. I think it took multiple attempts to get the Mini Display Port/Thunderbolt to HDMI working fully with sound and video. It also depends upon the adapter, I've had a few cheap ones that did not work correctly at all.