Issues with serial connection with printer.

Hello,

After I uploaded Marlin to my setup reprap prusa i3 with ramps 1.4 shield and arduino mega board and full graphics display, I tried to connect to the printer with repetier and when I try to send commands to it it just doesn't respond but the LCD does show the menu,
Also after a little "upgrade" I made to my arduino with another Voltage regulator to the current one in parallel it keeps over heating when the LCD's back light is ON anyone else encountered this problems?

Thanks for reading.

make sure the BAUD settings in your configuration.h file is the same as the connection rate in windows, just search for BAUD in the configuration.h file,but not the bluetooth BAUD rate, that will do nothing, and checkin windows by going to device manager and clicking on COM devices, there should be only the printer connected there, check its propporties and find out what its connection speed is and use that value for the BAUD rate, it should be either 115200 or 128000, the default in marlin is 250000, which i dont believe windows works with

#define BAUDRATE 128000

thats the line you are looking for in you configuration.h file