MacBook – “No signal” at external display connecting to MacBook Pro using DisplayPort

displaydisplayportmacbook pro

I’ll be really grateful for any recommendations in solving the problem of connecting an external monitor to MacBook Pro using a miniDisplayPort / DisplayPort cable.

For a long time I used AOC I2369VM (1080p, 60Hz) as an external monitor for MacBook Pro (Early 2011, 13”, macOS 10.13.6) using a miniDisplayPort / DisplayPort cable, and it’s work perfectly. A couple of days ago I bought a new AOC I2475PXQU (1080p, 60Hz) and it doesn’t work: the laptop “sees” the monitor and creates a second desktop, however on the monitor I see the message “No signal” only. In some cases, the laptop freezes or spontaneously reboots when the monitor is connected or disconnected. When I change the image output settings to 1080i or 720p, sometimes the second desktop appears on the monitor (but in most cases I see the message “No signal” only). For some reason, the monitor is defined as I2475W1 in the system settings. I tried using a different cable with the same connectors, however this didn’t fix the issue. I performed a reset of NVRAM, PRAM and SMC — this didn’t help either. In addition, I performed Apple Hardware Test — there are no errors. Also, I connected other devices to this monitor using HDMI, and they worked perfectly.

Update: According to the monitor menu, H. Frequency is 45 KHz at 720p and 34 KHz at 1080i; V. Frequency is 60 Hz at any settings. When other devices connected by HDMI, H. Frequency is 68 KHz and V. Frequency is 60 Hz.

How can I localize and fix the issue? Can the miniDisplayPort / DVI adapter solve the problem? (I have a DVI cable.) Thank you.

Best Answer

most probable cause is the mDP cable different cable / adapter should solve the problem