Cable for external monitor iMac 2017

[paulfromhudds]

Hi, hope someone can point me in the right direction.

I have am iMac 2017 4.2ghz 64mb ram with 8tb fusion drive. I have just purchased a BenQ PD2700U monitor. It comes with various cable to link, Dp to mini-DP cable and a HDMI to hdmi cable. The iMac has no hdmi or DP. It has Four USB 3 ports, Two Thunderbolt 3 (USB-C) ports with support for: DisplayPort. Thunderbolt (up to 40 Gbps) USB 3.1 Gen 2 (up to 10 Gbps).

I have bought a USB C to HDMI Cable, USB Type C to HDMI Cable (Anti-Interference, Thunderbolt 3/4 Compatible).

When connected it says on the Benq monitor 'No cable attached but in the System prefs it shows the monitoe as a second monitor but the monitor is not working??

I have read on the web that the USB-C socket is identical to the thunderbolt socket but internally different. Have I bought the wrong cable?

When looking on Amazon most listings seem to say USB-C (Thunderbolt), it's very confusing.

Any help would be appreciated in getting the monitor to work.

I have attached the ports for both devices.

Thank you in advance

 

[dwig]

...
I have read on the web that the USB-C socket is identical to the thunderbolt socket but internally different. Have I bought the wrong cable? ...

"USB-C" is only a description of the connector and is NEVER EVER a description of the data, video, and/or power ability of the port. Thunderbolt 3 & 4 uses the USB-C connector. Most "Thunderbolt 3" and "Thunderbolt 4" ports will also communicate with USB-3.x devices, hence the common, though somewhat erroneous "USB-C (Thunderbolt)" phrase.

You iMac can supply Tb3 data, Dp video (Display Port Alt Mode), and USB 3.x data via its USB-C connector. Your monitor should work with any properly working USB-C to HDMI cable. The fact the the iMac is "seeing" the monitor but the monitor is not displaying anything may mean that the monitor is not in a mode to auto-detect which port is in use and is defaulting to one of the other port. Dive into the monitor's menus looking for the input selection and force HDMI. Alternately, the cable could be faulty.

 

[paulfromhudds]

"USB-C" is only a description of the connector and is NEVER EVER a description of the data, video, and/or power ability of the port. Thunderbolt 3 & 4 uses the USB-C connector. Most "Thunderbolt 3" and "Thunderbolt 4" ports will also communicate with USB-3.x devices, hence the common, though somewhat erroneous "USB-C (Thunderbolt)" phrase.

You iMac can supply Tb3 data, Dp video (Display Port Alt Mode), and USB 3.x data via its USB-C connector. Your monitor should work with any properly working USB-C to HDMI cable. The fact the the iMac is "seeing" the monitor but the monitor is not displaying anything may mean that the monitor is not in a mode to auto-detect which port is in use and is defaulting to one of the other port. Dive into the monitor's menus looking for the input selection and force HDMI. Alternately, the cable could be faulty.

Hi, thank you so much, I thought this and went through the options. I must have mist one, been through them all again and selected the correct one and bingo. Thank you 😊

 

[Fishrrman]

You could use:

Thunderbolt/USBc (iMac) to displayport (display)
Thunderbolt/USBc (iMac) to minidisplayport (display)
Thunderbolt/USBc (iMac) to HDMI 2.0 (display)

I'd try USBc-displayport first.
When connected to the proper cable, the Tbolt/USBc port is actually putting out a "display" signal, not a "USB" or "tbolt" signal (that would connect to an external drive, etc.).