Macbook Pro Doesn't Recognize External Monitor

[nightwolf]

Hey guys, so I have Macbook Pro retina 15" with NVIDIA GeForce GT 750M and a ViewSonic VX2453mh-LED.

2-3 weeks ago I plugged it in via HDMI cable and MB instantly recognized it, and I could adjust it in Preferences>Display.

I haven't used it since and today I updated to the latest Yosemite (already had Yosemite) and when I plug the monitor nothing happens. I tried:
Changing HDMI port on monitor
Plug cables in and out
Leave it plugged in and restarting MB
Holding Command+Option+P+R when booting MB

Thanks!

 

[chscag]

Your title states that your MacBook Pro does not recognize your Viewsonic monitor. What happens when you open System Preferences, Displays? Is the Viewsonic seen? If it's not seen, I would start trouble shooting by replacing your adapter and cable to the monitor. Updating to the latest version of Yosemite should not have any effect on whether or not the monitor is recognized. If it was recognized by Yosemite 10.10.3, it will be recognized by Yosemite 10.10.4.

 

[nightwolf]

Your title states that your MacBook Pro does not recognize your Viewsonic monitor. What happens when you open System Preferences, Displays? Is the Viewsonic seen? If it's not seen, I would start trouble shooting by replacing your adapter and cable to the monitor. Updating to the latest version of Yosemite should not have any effect on whether or not the monitor is recognized. If it was recognized by Yosemite 10.10.3, it will be recognized by Yosemite 10.10.4.

Hi mate, no Viewsonic is not seen and there is no arrangement tab in Preferences>Displays. I tried holding Option key and clicking on Detect but nothing happened.

Tomorrow I'm getting VGA to Mini DP adapter and I'll try it with my VGA cable, but my HDMI cable (brand new, used it only 1-2 times) worked when I connected Viewsonic to MB, is just today that MB is not recognizing the monitor after the update.

 

[Slydude]

May I suggest trying a different cable even though you have only used the current one a few times. I had a cable recently that failed quite suddenly. It literally worked one minute, I disconnected the cable to rearrange some gear. Connected the cable a few minutes later and it was utterly useless.

I've also had similar problems with some adapters (particularly the cheaper ones).

 

[nightwolf]

May I suggest trying a different cable even though you have only used the current one a few times. I had a cable recently that failed quite suddenly. It literally worked one minute, I disconnected the cable to rearrange some gear. Connected the cable a few minutes later and it was utterly useless.

I've also had similar problems with some adapters (particularly the cheaper ones).

Just tried another HDMI cable that is functional and it didn't help.

I assume is something on the software side (Yosemite) because monitor is functional, HDMI cable is new and it used to work last time I used MB, this issue happened suddenly without reason.

 

[mad_macs]

Safemode or SMC reset

Hey guys, so I have Macbook Pro retina 15" with NVIDIA GeForce GT 750M and a ViewSonic VX2453mh-LED.

2-3 weeks ago I plugged it in via HDMI cable and MB instantly recognized it, and I could adjust it in Preferences>Display.

I haven't used it since and today I updated to the latest Yosemite (already had Yosemite) and when I plug the monitor nothing happens. I tried:
Changing HDMI port on monitor
Plug cables in and out
Leave it plugged in and restarting MB
Holding Command+Option+P+R when booting MB

Thanks!

In my support I've been wondering if I'd ever run into this issue myself. The one thing you don't list is probably the first thing that I'd try just because of the nature of how the Mac detects hardware. Of course I'm sure the monitor is set to the right source with what you've gone through for troubleshooting the problem. Have you tried starting in Safemode? Reset SMC?

Reset SMC:

1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer. *
Note: The LED*on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.