Hello, I recently got my hands on an Ender 3 v3 SE experiencing the blue screen of death issue. I tried redoing the firmware to no success so I replaced the main board thinking this would solve the issue. It did solve the issue however the previous owner not knowing much about electronics repair had set the power supply to 240V in my 110V region thinking it would fix the problem. That seems to have damaged some other component and i am trying to narrow down the most likely culprit. Upon powering up the printer it seems to be going into the leveling function automatically but doesn’t get far. All it does is move up the Z axis a little and sit there, the print head does not get hot. I am wondering what the normal sequence of events in the bed leveling routine are. Does it move up the Z a bit to make sure it doesn’t burn the plate then begin heating the print head or does it move the head around more than that before it tries to heat? I am thinking it’s either the print head or the stepper motors but don’t have a ton of experience with 3d printers. Thanks for any help and have a great day.
Hello @zombiecnacer12 …! 
Welcome to the Creality Forum…! 
If you don’t get it working you should be able to search on Amazon and get a motherboard for it…
Mainboard from Aliexpress.
Have you tried resetting the voltage switch, sometimes it looks in the right spot but hasnt really clicked into place. Usually having it set to 240 in a 110 environment doesnt kill the board, but the other way round it will.
As 3D4Everyone mentioned, having it set for 240v and plugging it into 110v, generally will not kill it, nor would 60hz instead of 50hz.
First thing I would do is as 3D4Everyone said, " reset the switch".
By this, I would (with it un plugged) switch to 240v and then back to 110 making sure it clicks right.
Plug it in and test it. If still not good. Turn off ,take out the motherboard you replaced and then re- wire it back in.