Mac mini doesn't display an image on startup when using USB-C to DisplayPort

gusping

macrumors 6502a
Original poster
Mar 12, 2012
616
137
London, UK
I have to switch to an HDMI cable to log in, then if I switch back to using the DisplayPort cable it works fine. Other times switching to HDMI cable to log in doesn't work, and I have to force turn off the machine at the back. Then.... 50% of the time it loads up in recovery mode at the reset password screen. Any ideas? I have tried many USB-C to DP cables and the DisplayPort works fine on the monitor as my 2014 MBP works sweet as a nut on it.
 

Sun Baked

macrumors G5
May 19, 2002
14,874
57
Do you have filevault turned on?

If so, try turning it off. This won't turn off file encryption, only turns off the added password layer on the drive.
 

gusping

macrumors 6502a
Original poster
Mar 12, 2012
616
137
London, UK
Tell us about the display that you have...
LG 27UK650-w. Works fine with my 2014 MBP using TB2 - ‘DisplayPort, so its all about the new Mac mini having issues.
[doublepost=1543744545][/doublepost]
Do you have filevault turned on?

If so, try turning it off. This won't turn off file encryption, only turns off the added password layer on the drive.
Yes i do. I’ve read a few things about turning filevault off so perhaps it’s worth a go. Resetting the NVRAM helped for about 6-7 boots, but now it’s back to not working. I’ll give it a go. Thanks
 

dimaspivak

macrumors newbie
Dec 2, 2018
13
7
Same issue here! I'm running 3 27" LG 4K displays (2 Thunderbolt 3 to DisplayPort, 1 HDMI to HDMI) on a maxed-out 2018 Mini. Not only would I occasionally get "No signal" on boot (pro tip: hold Command+Opt+Ctrl+Eject to shutdown when you can't see anything) I also encountered random flickers where one or more of the monitors would go black for a second. I was ready to exchange the Mac but then tried out using Thunderbolt 3 to HDMI and the problems haven't resurfaced. Really appears to be some kind of hardware issue specific to DisplayPort and the Thunderbolt 3.
 

gusping

macrumors 6502a
Original poster
Mar 12, 2012
616
137
London, UK
Same issue here! I'm running 3 27" LG 4K displays (2 Thunderbolt 3 to DisplayPort, 1 HDMI to HDMI) on a maxed-out 2018 Mini. Not only would I occasionally get "No signal" on boot (pro tip: hold Command+Opt+Ctrl+Eject to shutdown when you can't see anything) I also encountered random flickers where one or more of the monitors would go black for a second. I was ready to exchange the Mac but then tried out using Thunderbolt 3 to HDMI and the problems haven't resurfaced. Really appears to be some kind of hardware issue specific to DisplayPort and the Thunderbolt 3.
I was thinking about that, but HDMI to displayport as i have the 2 HDMI ports on my monitor for my consoles. I just reinstalled a fresh copy of Mojave and it happened so i'm just about to wipe it again..... Already got several cables to take back to Amazon. Do I risk buying another one..... FFS

Edit: It seems HDMI to DP doesn't work, only the other way round. I'm going to return it. Such a shame as i really want to keep it, but Apple quality fails once again.
 

solidify

macrumors newbie
Dec 12, 2018
26
3
Can you please tell us if there are any other changes?

The same thing happens to me, when I go to reboot is often comes back with a blank screen. I have to hold down the power button which shuts it off, but then it books back into a screw asking to reset my password.

I am using an adapter to go from the little USB port to the DisplayPort on my monitor.
 

dimaspivak

macrumors newbie
Dec 2, 2018
13
7
Can you please tell us if there are any other changes?

The same thing happens to me, when I go to reboot is often comes back with a blank screen. I have to hold down the power button which shuts it off, but then it books back into a screw asking to reset my password.

I am using an adapter to go from the little USB port to the DisplayPort on my monitor.
Use Command+Opt+Ctrl+Eject to avoid having to power down with the power button. That said, I replaced my Mac Mini and ran into the same issue there with new cables, so it appears to more than a one-off incident and am trying to work through it with Apple Support.
 
  • Like
Reactions: solidify

solidify

macrumors newbie
Dec 12, 2018
26
3
Use Command+Opt+Ctrl+Eject to avoid having to power down with the power button. That said, I replaced my Mac Mini and ran into the same issue there with new cables, so it appears to more than a one-off incident and am trying to work through it with Apple Support.
Ok, thanks for that tip. When you use Command+Opt+Ctrl+Eject, does it still boot to the reset password thing?

Also, please keep us updated with what you learn from Apple Support, thanks :)
 

dimaspivak

macrumors newbie
Dec 2, 2018
13
7
Ok, thanks for that tip. When you use Command+Opt+Ctrl+Eject, does it still boot to the reset password thing?

Also, please keep us updated with what you learn from Apple Support, thanks :)
No, it does a graceful shutdown (unlike holding the power button). Will let you know if they figure it out.
 
  • Like
Reactions: solidify

ncrypt

macrumors 6502
May 16, 2012
312
187
UK
I've also been experiencing the same issues as you guys:
  • USB-C to DP cable doesn't show any image whilst booting, and sometimes no image when waking from sleep
  • HDMI to HDMI seems to have no issues, however for some reason the image is slighter fuzzier despite running at the same resolution
  • Monitor is an LG 27UD68
but then tried out using Thunderbolt 3 to HDMI and the problems haven't resurfaced. Really appears to be some kind of hardware issue specific to DisplayPort and the Thunderbolt 3.
Based on this, I'm going to order a USB-C to HDMI cable and hope it all works out. Are you experiencing any further issues since switching to that cable?
 

dimaspivak

macrumors newbie
Dec 2, 2018
13
7
I've also been experiencing the same issues as you guys:
  • USB-C to DP cable doesn't show any image whilst booting, and sometimes no image when waking from sleep
  • HDMI to HDMI seems to have no issues, however for some reason the image is slighter fuzzier despite running at the same resolution
  • Monitor is an LG 27UD68

Based on this, I'm going to order a USB-C to HDMI cable and hope it all works out. Are you experiencing any further issues since switching to that cable?
Since switching to USB-C/HDMI, those monitors work great. Sadly, the third monitor on HDMI/HDMI occasionally flickers to black and even sometimes takes a pink/green hue or drops out until a restart. I imagine there's a bug with the Intel graphics chipset drivers that will require a firmware update.
 

ncrypt

macrumors 6502
May 16, 2012
312
187
UK
Since switching to USB-C/HDMI, those monitors work great. Sadly, the third monitor on HDMI/HDMI occasionally flickers to black and even sometimes takes a pink/green hue or drops out until a restart. I imagine there's a bug with the Intel graphics chipset drivers that will require a firmware update.
Thank you, ordering a USB-C to HDMI right now!
 

SkiHound2

macrumors regular
Jul 15, 2018
164
111
Have you called Apple? I just received a Mini that would not display anything using either HDMI or USB 3 to display port. Tried multiple cables and monitors assuming I was doing something wrong. I called Apple. The tech asked a few questions about what I'd tried and then said this was an issue that needed to be investigated by Apple so I needed to return the Mini. I definitely got the impression this was not an isolated issue, though I've not read about others having the issue on this forum. And usually any issues that are going on will be reported here.
 

ncrypt

macrumors 6502
May 16, 2012
312
187
UK
I did call Apple support and the first thing the advisor asked me to do was reinstall macOS and said if that didn't work then it can't be the software at that point... didn't even try an SMC or PRAM reset, or suggest using different cable.

She advised I just go to a store for a replacement unit if the reinstall didn't work it.

I tried the reinstall, and it didn't make any difference.
 

rgeraght

macrumors newbie
Mar 31, 2011
11
13
I'm running into the same problem with new Mac mini 2018, cannot boot properly and get blank screen most of the time (only about 10% of cold boot works okay, restart always fine). Everything else works fine, including restart, just not booting from cold.

Once I turn FileVault off it then starts working fine, but not with FileVault on. This seems related to T2 chip, as that controls encryption now.

With FileVault off I can see monitor turn off during boot but then come back on after 30 seconds.

Loving the new Mac mini, but the boot problems with FileVault on (in my case) just seem weird.
 

Kurri

macrumors 6502
Mar 6, 2009
380
117
i returned my mini because of this. I would have to hold down the restart button to get an image. Didnt know what to do and after spending 2K on the machine I didnt want to have to put up with it. Just waiting for a new imac.........waiting......and waiting......
 

wdh_2019

macrumors newbie
Feb 27, 2019
4
0
CA
i returned my mini because of this. I would have to hold down the restart button to get an image. Didnt know what to do and after spending 2K on the machine I didnt want to have to put up with it. Just waiting for a new imac.........waiting......and waiting......

Same problem here! I'm on my second Mac mini with the problem, and have tried everything (I think I've reinstalled the OS over 10 times, trying out different things). I'm fairly certain that the problem occurs when FileVault is on. So has everyone tried turning it off....does it resolve? I'm trying to decide if I should keep this Mac mini or return it. It's an annoying problem. As expected, apple tech support says they don't know of an issue and must be corrupt files on my computer. Meanwhile I've never had a problem with my MBP, so there is something up with Mac mini and FileVault and maybe T2 chip.
 
Last edited:

Kurri

macrumors 6502
Mar 6, 2009
380
117
Same problem here! I'm on my second Mac mini with the problem, and have tried everything (I think I've reinstalled the OS over 10 times, trying out different things). I'm fairly certain that the problem occurs when FileVault is on. So has everyone tried turning it off....does it resolve? I'm trying to decide if I should keep this Mac mini or return it. It's an annoying problem. As expected, apple tech support says they don't know of an issue and must be corrupt files on my computer. Meanwhile I've never had a problem with my MBP, so there is something up with Mac mini and FileVault and maybe T2 chip.
They have to know about the problem. I was on the phone for days with them about this. You called, i called, i’m Guessing more called than just us. They just dont know a fix yet
 

gusping

macrumors 6502a
Original poster
Mar 12, 2012
616
137
London, UK
They have to know about the problem. I was on the phone for days with them about this. You called, i called, i’m Guessing more called than just us. They just dont know a fix yet
It is a very widespread problem so you'd hope so. It is a bit of a joke there's mean no official word on this. Standards slipping as usual.
 

wdh_2019

macrumors newbie
Feb 27, 2019
4
0
CA
They just asked me to send them a "disk image" so the engineers can help identify the issue. I'm not optimistic they'll find anything. They said it will take 2 days....well 2 days later still waiting. Meanwhile I have ~3 more days to decide if I should return the mini and just go with another MBP. Problem is I don't need another laptop right now and it's 1K more to get same specs. Frustrating.