Chosen Solution
I was using my Macbook connected to a Dell P2219 monitor using usb-c hub and hdmi cable without closing the internal display(at lowest brightness). But the display turned to blue/purple and mostly black after I unplugged all the cables. It stays the same after few hours and only works normally for external monitor. I already tried to uninstall some possible applications, update the system(but still 10.14.6) and reset the NVRAM, didn’t work. Pic:
The T-CON board over-heated killing it. This often happens when the back vents are blocked. The heat sink heat transfer fins are very close to the T-CON board as Apple moved it into the main case to thin down the display lid.
The problem is you can’t replace the T-CON board its self you need to replace the entire display! If you still have AppleCare+ coverage I would let Apple fix this as that would be the cheapest repair. If its not covered here’s the part you’ll need: MacBook Pro 13" Display - SilverMacBook Pro 13" Display - Space Grey We don’t have a guide for the 2018 model but the process is the same as the MacBook Pro 13" Touch Bar 2017 Screen Replacement.
