MBA 2020 can't connect to external monitors

[kirbyrun]

I've been trying to connect my wife's new MBA 2020 to two different external monitors, with no luck. Both have worked as external displays in the past with multiple other Macs.

The first is an old Dell display with DVI out. I have a DVI to Thunderbolt 2 cable, so I plugged that into Apple's Tbolt 3-to-2 adapter (here: Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter), but no luck.

I also have an old iMac (2011) sitting around that I've used as an external display for YEARS via Target Display Mode. It has Tbolt 2, so used the same adapter to plug it into the laptop. When I hit Cmd-F2, the screen of the iMac goes black, but the MBA doesn't show any options for a second display. It's like the iMac KNOWS it's supposed to be receiving something over Tbolt, but the MBA doesn't see it.

What the heck am I doing wrong?

(Edited to correct VGA to DVI)

 

[Daveed]

I have the exact same problem. I also am trying to connect my wife's MBA (2020) to an iMac (2011) that I have been using successfully in Target Display Mode with my MacBook Pro (2017).

In both cases I using the same Thunderbolt 2 cable and Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter. When using it with the MBA, I am seeing no sign of life when I hit Cmd-F2. I have tried all sorts of things to get this to work with the MBA, all in vain.

I spent about an hour with Apple's support team providing information. They are working on the problem, with one possibility being an issue in the latest Catalina update. I am running 10.15.4 on both my MacBook Pro (which is working) and on my wife's MBA (which isn't working). I updated the MBA to the latest Catalina version before trying Target Display Mode, so I don't know if it would have worked prior to the latest Catalina update.

In the meantime, please post again if you find a solution, and I'll do the same.

 

[viss]

Are you charging the MBA while its connected to the 2nd display ? I have mine connected to the Apple TB display and to make it work (with any MB) the laptop has to be on the charger.

 

[sundialsoft]

I bought a new LG USB-C 4k monitor for my wife's home office. Works well with the new MBA and powers the laptop and provides USB ports on the monitor. I can also use my old MBA but only at HD res.

 

[Daveed]

Are you charging the MBA while its connected to the 2nd display ? I have mine connected to the Apple TB display and to make it work (with any MB) the laptop has to be on the charger.

Thanks for the tip. I am indeed charging the MBA while it is connected to the 2nd display, but unfortunately the Target Display Mode is not working.

 

[kirbyrun]

Thanks for the tip. I am indeed charging the MBA while it is connected to the 2nd display, but unfortunately the Target Display Mode is not working.

Ditto me -- charging the laptop while trying to use the external monitor. I finally gave up, BTW, and just bought my wife a cheap HDMI monitor, which works flawlessly.

 

[saulinpa]

The TB2<->TB3 adapter does not support video except for TB monitors. You need a USB-C hub or adapter or get a full TB dock.

 

[chrfr]

Ditto me -- charging the laptop while trying to use the external monitor. I finally gave up, BTW, and just bought my wife a cheap HDMI monitor, which works flawlessly.

You'd need a USB-C to VGA adapter, not a Thunderbolt adapter. The HDMI display is probably a better option.

 

[RMainz]

Daveed or Kirbyrun, Do you have any updates?

Exact same situation here. I was previously using a supported iMac for Target Display Mode. Thunderbolt2 cable and Thunderbolt to USB-C adapter. The setup works on old MBA mid-2012 (only the Thunderbolt cable) and it works on MBP late 2016 (with Thunderbolt to USB-C adapter).

I too purchased a new MBA 2020, immediately did the macOS update 10.15.4, and then tried Target Display Mode. It does not work on MBA 2020 with latest update. Unknown if the macOS update made a difference, as I did not test it "out of the box" with macOS 10.15.3.

I have tried using the Target Display Mode on a brand new Admin acct and home folder with admin rights that migrated from the MBA mid-2012, neither will connect/target display mode to/from the iMac.

My next troubleshooting tip is to try restarting this MBA 2020 in Safe Mode (restart with shift key pressed). If that is successful, I will repost.

 

[kirbyrun]

Daveed or Kirbyrun, Do you have any updates?

Nothing since my last post -- I gave up and switched my wife to an HDMI monitor, which works fine.

As saulinpa above indicates, it may be a hardware issue. Even though multiple Apple Support folks told me it SHOULD work as I have it set up, it just doesn't. And I tried Safe Mode, too, BTW, and nothing.

 

[deeddawg]

Thread title is rather misleading.

As posted, 2020 MBA's work fine with external monitors.

While there's apparently something with the TB2/TB3 adapter, that's not necessarily specific fo the 2020 MBA.

 

[RMainz]

Daveed or Kirbyrun, Do you have any updates?

Exact same situation here. I was previously using a supported iMac for Target Display Mode. Thunderbolt2 cable and Thunderbolt to USB-C adapter. The setup works on old MBA mid-2012 (only the Thunderbolt cable) and it works on MBP late 2016 (with Thunderbolt to USB-C adapter).

I too purchased a new MBA 2020, immediately did the macOS update 10.15.4, and then tried Target Display Mode. It does not work on MBA 2020 with latest update. Unknown if the macOS update made a difference, as I did not test it "out of the box" with macOS 10.15.3.

I have tried using the Target Display Mode on a brand new Admin acct and home folder with admin rights that migrated from the MBA mid-2012, neither will connect/target display mode to/from the iMac.

My next troubleshooting tip is to try restarting this MBA 2020 in Safe Mode (restart with shift key pressed). If that is successful, I will repost.

Update: Neither Safe Boot nor booting into macOS Recovery and running First Aid made any difference. Since my exact setup works on other computers (minus this MBA 2020), I know the Apple Thunderbolt 3/2 adapter and Apple Thunderbolt cable works fine. Have tried both ports on MBA 2020 and plugged into power vs battery.

Highly doubt this a hardware issue and believe this to be unique to MBA 2020, assuming its macOS version(s).

(Note, the original poster was explaining MBA 2020 to a non-Apple external monitor and Target Display Mode...)

I have not yet tried connecting to a non-Apple external monitor. I will try that next using an Apple USB-C Digital AV multiport adapter (using HDMI) to external monitor. Though, that defeats the point of using my supported iMac in Target Display Mode to this MBA 2020...

 

[RMainz]

Update: I connected this MBA 2020 to an Apple USB-C Digital AV multiport adapter (using HDMI) to external monitor HP Pavilion 22xw. The MBA 2020 immediately displayed to an external HDMI monitor. Unplugged, and then re-tried the Thunderbolt 3/2 to Thunderbolt to iMac, Command-F2. No go on Target Display Mode.

Not that it should have worked, but I tried daisy-chaining MBA 2020 to Apple USB-C Digital AV multiport adapter to Thunderbolt 3/2... Naturally that did not work due to the adapter only displaying power symbol, its pass-thru USB-C is for power cable only, not Thunderbolt 3...

I'm out of options for connecting this MBA 2020 to supported iMac in Target Display Mode for the time being. Given these covid-19 work from home times, I guess my wife and I will have to thumb wrestle over who gets to use the HDMI external monitor. Fun.

 

[saulinpa]

Apple's support for anything technical sucks but you should still open a ticket with them. Then request escalation.

Older iMacs used DP so I can uderstand the TB3-TB2 adapter not working and needing a USB-C to mDP adapter instead. The 2012 and newer iMacs used TB so the adapter should be supported.

 

[deeddawg]

I have not yet tried connecting to a non-Apple external monitor.

HDMI 1080p works fine via a basic USBC hub I've had for 2-3 years.

 

[KPOM]

Nothing since my last post -- I gave up and switched my wife to an HDMI monitor, which works fine.

As saulinpa above indicates, it may be a hardware issue. Even though multiple Apple Support folks told me it SHOULD work as I have it set up, it just doesn't. And I tried Safe Mode, too, BTW, and nothing.

The TB2-TB3 adapter is strictly for Thunderbolt 2 devices. It doesn’t pass through a video signal. There are plenty of USB-C to VGA adapters available (and cheaper than Apple’s adapter). I’d suggest getting one of them.

 

[kirbyrun]

The TB2-TB3 adapter is strictly for Thunderbolt 2 devices. It doesn’t pass through a video signal. There are plenty of USB-C to VGA adapters available (and cheaper than Apple’s adapter). I’d suggest getting one of them.

VGA wouldn’t help me at all, since I don‘t have a VGA monitor. But as I’ve mentioned, I just went ahead and bought a cheap HDMI monitor and she’s happy with that.

What I wonder is: is there any adapter that would let the MBA 2020 drive the 2011 iMac in Target Display Mode?

 

[chrfr]

VGA wouldn’t help me at all, since I don‘t have a VGA monitor. But as I’ve mentioned, I just went ahead and bought a cheap HDMI monitor and she’s happy with that.

What I wonder is: is there any adapter that would let the MBA 2020 drive the 2011 iMac in Target Display Mode?

The only way to use Target Display mode from a 2011 iMac is, indeed, to use the Apple Thunderbolt 2 to 3 adapter. Post 16 is correct that the adapter doesn't pass through Mini DisplayPort video, but you're passing through a Thunderbolt signal from the 2011 iMac. In general, though, trying to use old iMacs has external displays has gotten less and less reliable as they age.

 

[saulinpa]

What I wonder is: is there any adapter that would let the MBA 2020 drive the 2011 iMac in Target Display Mode?

Try a USB-C to mDP adapter and mDP cable. Or USB-C to DP and DP to mDP cable.

 

[chrfr]

Try a USB-C to mDP adapter and mDP cable. Or USB-C to DP and DP to mDP cable.

Thunderbolt is required to connect a 2011 iMac in Target Display mode. DisplayPort/Mini DisplayPort will not work at all.

 

[saulinpa]

Thunderbolt is required to connect a 2011 iMac in Target Display mode. DisplayPort/Mini DisplayPort will not work at all.

Right. But some 2011's didn't have TB.
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VGA wouldn’t help me at all, since I don‘t have a VGA monitor. But as I’ve mentioned, I just went ahead and bought a cheap HDMI monitor and she’s happy with that.

Your opening post said you had a Dell display with VGA?

 

[chrfr]

Right. But some 2011's didn't have TB.

Those which don't have Thunderbolt most likely don't support TDM at all, given that the Apple support document covers two types of iMacs: Those with Thunderbolt, and 27 inch iMacs with Mini DisplayPort.

 

[kirbyrun]

Your opening post said you had a Dell display with VGA?

Misspoke. It’s DVI. My bad. Edited the original post.

 

[Daveed]

Daveed or Kirbyrun, Do you have any updates?

Exact same situation here. I was previously using a supported iMac for Target Display Mode. Thunderbolt2 cable and Thunderbolt to USB-C adapter. The setup works on old MBA mid-2012 (only the Thunderbolt cable) and it works on MBP late 2016 (with Thunderbolt to USB-C adapter).

I too purchased a new MBA 2020, immediately did the macOS update 10.15.4, and then tried Target Display Mode. It does not work on MBA 2020 with latest update. Unknown if the macOS update made a difference, as I did not test it "out of the box" with macOS 10.15.3.

I have tried using the Target Display Mode on a brand new Admin acct and home folder with admin rights that migrated from the MBA mid-2012, neither will connect/target display mode to/from the iMac.

My next troubleshooting tip is to try restarting this MBA 2020 in Safe Mode (restart with shift key pressed). If that is successful, I will repost.

RMainz, I spent several hours on the phone with Apple support and trying to figure out on my own how to connect my wife's 2020 MBA to an iMac using a proven Target Display Mode setup, and I finally gave up. I am connecting it to an inferior LG monitor instead, using HDMI.

 

[AppleZombie]

Has anyone found an answer to this yet? I got my 2020 MBA this week and unfortunately didnt do proper research on using my 2011 iMac as a display for the MBA. Nothing works with TB3 to TB2 adapter and TB2 Cable. I have read that a TB3 port will probably work, but I am unwilling to fork out $200 not knowing if it will work. Apple support has been no help. The TB3 to TB2 clearly states that it will work and is compatible with MBA, disappointed.