First order of business. Get rid of the LCD from the board for now and re-upload the firmware code. Make sure you closed the Pronterface and Repetier before you upload the firmware. If they we open, close them and re-upload the code again ( I dont know the reason why it worked for me but it did).
I would suggest you not to open Pronterface at all (restart the computer if necessary). Use only Repetier… for some reason when I was using pronterface and then closed and switched to Repetier, the manual controls didn’t work. When this happened I closed both the softwares and reuploaded the firmware again and opened Repetier to connect to the printer.
If you have firmware upload issues, download a stable older version of Arduino IDE and then try again.
If the above suggestions doesnt work or have some doubts in execution, leave a message here or do the below steps…
Please attach your firmware code here along with snapshots of the Repetier Host (before you click connect, immediately after you click connect and when the status shows Idle). Please confirm that you clicked the right port number in Repetier software that matches the port you used to upload the arduino code.