External Displays won't come back on

I hope it keeps working out for you!

I also just got the motherboard replaced (picked the computer up today from the repair shop). However, I'm going to give it a few weeks before I celebrate anything - from what I've experienced and read, this is most likely a combination of software and hardware error.

So I got a new motherboard yesterday. Today, when trying to wake the MBP16 up (yes, connected to an external display) it had crashed just in the same way as before.

The new motherboard did nothing to help with the problem.

Much like Wayne (post above here) I thought I should stick with 10.15.1, which was what was installed on the computer when it came back from service. For some weird reason I decided not to, and ... well, here I am on 10.15.5, having the same problem again.

So - for all users who are still on 10.15.1, 10.15.2 or 10.15.3 - don't update. But then again, if you're here that means you did, and are now having problems.

Again to agree with Wayne, I think this has been going on for far too long. How do someone preassure a company like Apple, though? Looking at the Apple-store page, LG even released a screen designed to be used with the "single cable solution" for this MBP16. When that solution doesn't work - and you've payed well over 4000$ for the computer+screen - isn't that sort of a scam?

Based on your account this looks to be a hardware issue (either something failed or something was updated in a new revision). The macOS version seems to be irrelevant since many users (including me) are still having the issues on 10.15.6. I'm going to contact Apple for a repair under warranty. Here's hoping it helps.

So it seems to have fixed it temporarily where by if the macbook goes to sleep and it woken up within the hour or two it works but if its overnight the same issue persists in the morning.

Thanks, I reset my PRAM and when I restarted the fan came on high but soon slowed and it seems to be working now, we'll see.

I have the same problem. For me it's always my third display which is connected with HDMI (port doesn't matter).

I just put my Macbook into Eplehuset, the Norwegian distributor/partner of Apple, and they are replacing the motherboard. So we'll see if that fixes the issue..

I have the exact same symptoms. I've tried switching usb c ports for the monitors and disconnecting all external usb devices but it still happens. It's making the new macbook unusable without having to power cycle every time.

Plus there is no way to downgrade to mojave which at least is an option for others who upgraded to Catalina.

Apple support please look into this as a high priority.

TIA.

Same issue for me... the MacBook Pro doesn't recognize that it has the display connected to it (LG UltraFine 5K Display). This is usually when it wakes from an extended sleep. I have to restart the MacBook Pro, disconnecting and reconnecting the cable doesn't seem to help. It is connected via the Thunderbolt 3 cable that came with the display (uses one cable to charge and feed video). I have the display set as my primary display with menu and the MacBook Pro is the secondary display. Prior to this display I had the original Apple Thunderbolt Display that I connected with an adapter. Same thing was happening, so I thought it was the display and adapter, which is why I purchased the new display. I also changed the cable to the shorter Apple Thunderbolt cable because the LG supplied cable was too long.

I have the same problem with my new MacBook Pro 16" and external Apple monitor. It was fine for a morning but has been on/off all afternoon until I permanently disconnected it and swopped my work back to my trusty 2015 MacBook Pro 15" and external Apple monitor.

This needs a fix.

Same here. Running latest Catalina

• Connecting to external display results in exchange of endless flickering dark blue between the macbook and the displays (Apple thunderbolt monitor)
• Opening the macbook lid to wake it up while being connected to the display, results in the same kinda dark blue screen on the macbook with no way to move past it

Only restart helps :(

Same issue - really hope they fix it in the next release and it's released very soon. It really makes the machine unusable for me and yes, it's okay to expect to not have to reboot to fix the problem on a $3,000 plus machine.

I thought that helped me a few weeks ago.... nope, ended up having the same issue eventually. It's almost like something gets corrupted on a port... because I agree, changing ports seemed to help. It works perfectly only sometimes which makes me think something is "flushed" out every now and then. They really need to fix this issue - why should I have to buy a new monitor for a very picky laptop?

It stuff like this which makes me want to move over to Windows 10, at least they get the basic right, this has been going on for three months now, and still no fix. If you going to offer people Professional hardware then you should have a place witch supports them users, people use there hardware to make a living, and this OS problem is just amateur and tacky.

I went through almost all the observations made above so far for the past two months. And no real solution yet. Very frustrated. Beginning to suspect Apple wants us to buy its 5K$ monitor. Has anyone have a monitor other than LG5K/4K and better luck?