Another External Monitor not working question

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Another External Monitor not working question

Hello,

Mac book Pro 16" (2019). External Monitor is a Philips 298P4 21:9 wide screen. Probably at least 5yrs old. Will connect via HDMI (thunderbolt 3 to HDMI cable).

I have successfully connected to the monitor via a Moshi USB-C to Display port recently, a couple of days ago, but it won’t connect any longer. When it did connect it took a lot of

Plugging and unplugging and restarting to get it happening. Now nothing. I’ve booted in safe mode, reset the PRAM, reset the SRC, tried all the ports on the computer, plugged and unplugged repeatedly.

Now it just won’t register that it’s connected on the monitor. “Check cable” message on screen, Mac Book doesn’t see the monitor (via display prefs).

I think this cable was recommended by apple at one time.

There is no way to update the firmware on this monitor that I can tell. But I don’t think it’s the monitor. Oh also the Image on the display looks terrible. Real ‘Grainy’ can see the pixel edges on images and text.

Would anyone have any suggestions? I have search the forums, and while there seem to be a lot of external monitor questions, none really had my issue that I could tell.

Thanks,

Bk

MacBook Pro 16″, macOS 10.15

Posted on Oct 12, 2020 1:15 PM

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Answer 1

jdo_apple

Community Specialist

Oct 17, 2020 8:04 AM in response to Brian Kingman

Hello Brian Kingman,

We understand that you've had some issues connecting an external monitor to your MacBook Pro while using a USB-C connection.

Since the monitor connects successfully with an HDMI it's possible that the USB-C itself could be the issue. We have a few guides that help you make sure everything is properly configured and provide you with steps to troubleshoot.

Take care!

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Answer 2

Oct 18, 2020 11:31 AM in response to jdo_apple

Hello jdo,

Thanks for taking the time to reply. I did see those links, but no go. When you say "the USB-C itself" do you mean the cable or the connector on the computer? I did try all 4 ports on the computer, no luck.

the Cable is the one that Apple recommends, the Moshi Displayport to USBC.

I was thinking about using a USB-C Adapter to Thunderbolt 2 then connecting a Mini Displayport to Display port cable, but it specifically states on the package for that adapter that it won't work with mini-display port...

any other thoughts or suggestions?

thanks,

Brian

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Answer 3

raina_b22

Community Specialist

Oct 20, 2020 11:32 AM in response to Brian Kingman

Hi again, Brian Kingman,

By the "USB-C itself" we did mean the cable. We wanted to know if using a different cable would help. The reason being that the monitor works as expected with the HDMI cable and port. Our suggestion would be to try a different USB-C cable.

Take care!

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Answer 4

Oct 20, 2020 12:08 PM in response to Brian Kingman

to get a Mac display to become active, you need the Mac to query the display, and the display to answer with its name and capabilities. Otherwise, the display will not be shown as present, and no data will be sent to the display.

This query is only sent at certain times:

• at startup

• at wake from sleep

• at insertion of the Mac-end of the display-cable, provided everything on that cable is ready-to-go

• on invoking Option-(Detect Display) button in Displays preferences (from another display)

so try doing some of those things and see if the display comes alive.

Modern Displays with multiple ports are sometimes busy scanning the other ports, looking for an input, and miss the query from the Mac. They need to pay attention to the port you are actually using, or they will miss the query.

Some displays have On-Screen Display settings that can be used to tell the display a computer is attached on a certain port, or a certain port should be highest priority. Changing those may make your display more responsive.

Some displays include their own private "sleep" settings for the display alone. This can allow the display to enter its own sleep mode, on top of the Mac's not sending it data. A display that is sleeping on its own cannot respond to the Mac's query, and will stay dark.

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Answer 5

Oct 21, 2020 12:51 PM in response to raina_b22

Hi,

So I took my older Macbook pro that has the Thunderbolt 2 jacks and plugged in my Mini Displayport to Displayport cable (a different cable obviously), into the external monitor and an image came up immediately. That tells me that the monitor and the Display port input jack on the monitor are good.

I'll see if I can get a replacement USB-C to Display port for the computer I'm trying to work with (Mac book Pro 16").

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Answer 6

Oct 24, 2020 9:33 AM in response to Brian Kingman

Hello Helpful people.

I just received a new USB-C to DisplayPort cable. This time it's from "Cable Matters". Lo and behold, it worked immediately.

It looks like the cable that Apple recommends by name, doesn't work. That would be the "Moshi" brand.

This is really a drag tho, It wasn't an inexpensive cable and I can't seem to find my receipt to return it.

Thanks for all your help.

Bk

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Answer 7

Oct 21, 2020 12:52 PM in response to Brian Kingman

Thanks Grant,

good info. I need to replace my existing cable first.

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Answer 8

Oct 24, 2020 3:33 PM in response to Brian Kingman

That expensive Moshi cable is supposed to excellent. You should see if Apple will exchange or refund it.

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