Repetier loosing connection everytime i click print!

Ani2s

hello everyone,
i got a German reprap neo 300 and i tired my first prints yesterday. everything went well at the beginning but after a while whenever i try to print something the printer disconnects. and i have to reconnect it manually. also i noticed that the temperature of the extruder is always 11-12°.. so i checked the log and found out that the M109 is the reason for the disconnection. but couldn't fix it..
[Log]
; generated by Slic3r 1.3.0-dev on 2018-01-19 at 16:48:03

; external perimeters extrusion width = 0.50mm (4.97mm^3/s)
; perimeters extrusion width = 0.58mm (11.78mm^3/s)
; infill extrusion width = 0.58mm (15.71mm^3/s)
; solid infill extrusion width = 0.58mm (3.93mm^3/s)
; top infill extrusion width = 0.58mm (2.95mm^3/s)

M190 S85 ; set bed temperature and wait for it to be reached
M104 S255 ; set temperature
G28 ; home all axes
G1 Z5 F5000 ; lift nozzle
[/Log]

any idea?
Thank you

Repetier

A typical reason when bed is turned on and connection is lost is a under dimensioned power unit. Heated bed requires some ampere to work and if that can not be delivered voltage drops and that can cause brown out especially if printer is not powered by usb but from main power. Of course a short in bed power circuit would also cause that but I would expect the fuse to stop that.

You could measure the resistance of bed when everything is unconnected. Then you can compute power required and compare.