Chosen Solution
So the first time this happened was yesterday, and I waited for about 1 hour and the computer worked properly until 7-8 hours ago. In the time while it was working, I have closed and opened the lid multiple times but when I open it the last time (7-8 hours ago) it was the same problem and I waited like 5 hours but it didn’t fix itself. The problem is the backlight is turned on and the Apple logo on the back is lighting. I can adjust the brigthness and the backlight will change colors from black to nothing. (The outside of the surface and the screen is distiunguishible, the screen is like a black light.) The backlight of keys work properly. I connected my Macbook to an external monitor via HDMI and the external screen shows Mojave background, and when I enter my password and press enter it shows the background of my 1.st desktop, not the background of the external monitor. When logging in i didnt see my icon and password bar, the external screen just shows the background. When I’m in the computer, the mouse is visible in the external monitor but i cant click, click and drag, right click and there is no top bar and bottom bar. I can just move my mouse. I tried the Internet Recovery (Cmd+D if im not mistaken) and it showed in the external monitor the world icon and i entered my wifi there and so on. After a while it said your computer has no problems, and i tried to get it to safe boot. I can’t see anything on safe boot, just a gray screen, exactly like what happens when I normal boot. I think that the monitor connector might got off or something like that but i don’t want to open my computer and try to fix stuff without being sure of the actual problem. Also a friend of mine said take off the battery and put it back in, it might work. I’m not sure about what to do…
As you can see the default background on the external we know the GPU is working so the connection of the internal might need to be checked. But, lets review one more thing here as by default your external display would be in mirror mode not second screen mode, did you alter it? Thats, why you can’t see your icons or the background you set for your internal display. So what we need to do is try resetting the SMC following this Apple T/N How to reset the System Management Controller (SMC) on your Mac. Removing the battery as your friend suggested would end up doing the same thing. If that fails you’ll need to go into Safe mode so you can reset the display setting. Reference: Mac startup key combinations
