Second external display goes black after a few seconds

leifwm wrote:

So I have a MacBook Pro (15-inch, 2016) running Mojave 10.14.6 with a Radeon Pro 455 2 GB Intel HD Graphics 530 1536 MB.

Im using twi displays with it :

One is an Apple display that is working just fine. Here is the system info:

**Thunderbolt Display:**

Display Type: LCD

Resolution: 2560 x 1440 (QHD/WQHD - Wide Quad High Definition)

UI Looks like: 2560 x 1440

Framebuffer Depth: 30-Bit Color (ARGB2101010

)Display Serial Number: C02M20KEF2GC

Mirror: Off

Online: Yes

Rotation: Supported

Automatically Adjust Brightness: No

Connection Type: DisplayPort

The other is a Samsung SyncMaster 940b, Her is the system info also:

**SyncMaster:**

Resolution: 1024 x 1280

UI Looks like: 1024 x 1280 @ 60 Hz

Framebuffer Depth: 30-Bit Color (ARGB2101010)

Display Serial Number: HXCLB03121Mirror: Off

Online: Yes

Rotation: 90

Automatically Adjust Brightness: No

Connection Type: DVI or HDMI

Adapter Firmware Version: 0.00

The problem is the syncmaster goes black after a few seconds and it is still detected by my Mac. I'm using a dvi to usb-c conector with it. I tried many solutions that I found on-line but none has worked. I'm thinking this has to do with the monitor being to old generating some driver compatibility issue.

Please help!

Thanks in advance

In General, you must make the connection from output to display input in at most one single adapter; in most cases, you can not stack adapters.

Get help with video issues on external displays connected to your Mac - Apple Support
 https://support.apple.com/en-us/HT201177

See— for display numbers and compatibility

https://discussions.apple.com/thread/250115199?answerId=250211154022#250211154022

Less is needed to run a DisplayPort family or Thunderbolt Display than an HDMI display.

ref: https://discussions.apple.com/thread/250925829?answerId=251758918022#251758918022