Simple Fix for 2019 13" MBP Radeon480x eGPU 'internal screen shows only windows logo' bug
Found a simple solution for the internal screen not working and only displaying the windows logo. Works for me reliably now.
2019 Touchbar 13" Macbook Pro
AMD Radeon 480x in a Razer Core X Chroma enclosure
Since getting set up I've never been able to get both my external monitor and internal laptop screen to work at the same time while using windows. The internal screen locks to the windows logo.
MacOs Cold plugging: Doesn't work
MacOs Hot plugging: Everything works fine
Windows bootcamp Hot plugging: doesn't work (fan spins up but nothing on external monitor, no egpu detected
Windows bootcamp Cold plugging: works fine, but internal display wont show anything other than windows logo.
Discovered this a few days ago and it works every time for me.
1. With the eGPU plugged into the laptop, power on to the HD selection screen.
2. Still on the selection screen, unplug the TB3 cable
3. Hit enter, selecting the Bootcamp/Windows drive.
4. Immediately re-insert the TB3 cable as soon as the blue windows logo appears, before the spinning dots start.
From there it boots up perfectly, my external monitor using the eGPU and the internal screen using the iGPU.
Reading around on this issue it was pretty hard to find fixes that didn't involve bootloaders or giving up completely. This seems like a remarkably simple solution for an issue that's been an obstacle for a while now for me. I only really wanted to fix it to avoid screen burn from that bloody logo.
No other GPUs for me to test this with, might work on other cards too.
Hope this helps someone struggling with the same issue!
@theted, Glad to hear this is working for your eGPU setup. This technique is also referred to as timed hot-plug.
@itsage, thanks, that's handy to know for future troubleshooting.
I'd tried timed hotplugging in previous attempts to get around the issue, but to no avail.
Crucially, having the eGPU connected to the laptop during the initial boot and then disconnecting it to hotplug it seems to have solved it all for me.