I'm having an issue where my Mecool android box starts up but the display stays on the TVBOX logo. The system is operating as I can hear the noise when I scroll through the menu and can even play videos with audio, but the display stays at the TVBOX logo.
Which Mecool box is it?
Try leaving it off for about 30 minutes to let it cool down completely, you could help it along quicker by sticking it on a fridge shelf or by pointing a fan at it etc.
Once you are happy it has cooled properly, plug it in and power it on and see if it is still stuck, if not, you may be experiencing the same overheating issue that I had with a Mecool KM2.
I have others and they don't have the issue, so it only seems to happen on some of them.
If it isn't that, try doing a factory reset on it, and see if that helps.