bed don't heat in start-gcode (3 replies)

Good day to all,

My problem is that when I start printing, the extruder heats up normally but not the bed.
The printing begins that I am obliged to stop
Since the bed is not hot.
I launched M140 with pronterface and there it works.
I reversed the order of heating between bed and extruder in my start-gcode, same result.

Here is my start-gcode

*******************START*********************************
; generated by Slic3r 1.2.9 on 2017-01-31 at 09:26:48
; external perimeters extrusion width = 0.40mm
; perimeters extrusion width = 0.48mm
; infill extrusion width = 0.48mm
; solid infill extrusion width = 0.48mm
; top infill extrusion width = 0.48mm
G28 ; home all axes
G29 ; autoleveling
M106 ; fan on
M140 s100 ; temperature bed
M104 s240 ; temperature extruder
G1 Z -1.23 ;offset 1.23mm
M109 S240 ;wait for temperature to be reached
G21 ; set units to millimeters
G90 ; use absolute coordinates
M82 ; use absolute distances for extrusion
G92 E0 ; affecte à la position courante E -> 0
***********************************************************
***********************************************************
*******************END*************************************
G92 E0
G1 Z28.200 F7800.000
M107
M104 S0 ; turn off temperature extrudeur
M140 s0 ; turn off temperature bed
M107 ; fan off
M84 ; disable motors



I have a power supply 12V 20A, hotend E3D v6 and hotbed 21,4x21,4 dimension.

I use pronterface (under linux ubuntu 16.04) , slic3r , MarlinRC8, ramps 1.4 board, and mega2560 board with arduino.