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amityweb

macrumors member
Original poster
Oct 5, 2010
41
2
Wales
I added a second monitor to my new Macbook Pro 2020 model, via an adapter with a HDMI port. That worked when initially plugging it in. But when the Macbook sleeps and you wake it up, the monitor never came back on, I had to unplug it and plug it in again.

I now added a third monitor via a USB-C to VGA adapter, and the problem now exists with that monitor, BUT the second monitor seems to be working OK now. So when coming out of sleep the second HDMI monitor seems to be coming on OK, but its the third VGA monitor thats not.

This happens regardless what port they use on the Mac, so same issue when both adapters are swapped ports.

If I remove the 3rd monitor I cant get the original issue of the second monitor not coming on, only tried it a few times though. So that seems to be fixed.

When I remove the second HDMI monitor, so the VGA monitor with the problem still does not come on, so problem exists when its only the second monitor.

Its really strange I used to have this when I only had a second HDMI monitor, but now I added a third VGA one the problem seems to be fixed for the HDMI one.

Dont know if its related but the HDMI monitor takes about 10 seconds to come on when waking the Mac which is very annoying, especially as thats the one with the login. The VGA one comes on right away when I plug it in.
 
When you say you're connected via an adapter, I assume that means it's USB-C to female HDMI. Those things can be finicky. I've never had good luck with them, even on Windows machines. You might want to consider picking up a direct USB-C to HDMI cable like this one. Same thing for your VGA monitor.
 
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Yes, the Macbook only had 2 USB-C ports, and I have a VGA and HDMI monitor, so need an adapter.

Its the VGA one that has the issue now though. I got this adapter https://www.amazon.co.uk/gp/product/B07WG2J8RG/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

For the HDMI I got this adapter https://www.amazon.co.uk/gp/product/B081H13PXH/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

I wont be able to use a direct USB-C to HDMI cable because there are not enough ports. Or it would need to go via the 4-port adapter anyway which defeats the object. The USB-C to VGA does not work when its attached to the 4-Port adapter, so I have to connect that direct to the Macbook. That leaves me only one USB-C port so the 4-port needs to connect to that. The 4-port then has the power cable, HDMI and couple of USB devices.
 
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The VGA adapter takes a HDMI one too, I just put both VGA and HDMI through it and although works, both monitors no longer come on when coming out of sleep. So maybe it is adapter related.

Edit: Scrap that, the monitors through one adapter are mirrored, so will go back to original setup.
 
Still not working right, this is unbelievably annoying!!!

Does anyone know if Apple's own adapter works flawlessly or has this same issue? At Apple's prices I would expect it to work flawlessly. Only problem is I would need to spend £150 to connect 2 monitors which find ridiculous:

One for VGA: https://www.apple.com/uk/shop/product/MJ1L2ZM/A/usb-c-vga-multiport-adapter
One for HDMI: https://www.apple.com/uk/shop/product/MUF82ZM/A/usb-c-digital-av-multiport-adapter

I wonder if the non-Apple adapters sold on the Apple website, like Belkin, mean they also work flawlessly as they are slightly cheaper.

Although to be honest I cant see me spending all that for 2 monitors, its ridiculous to be honest that 3rd party ones dont work.

Its a coincidence both my adapters have the same issue and they are different brands, so I am concerned its a Apple software issue and it will exist even with Apples own products.
 
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