Temperature not transfering when slicing/printing files

I have been putting up with this problem for months, When I slice a part and send it thru my pc to print about half the times it transfers without the extruder temperature. It shows 0 on the attached screen and just lets the temperature drop. The heated bed works perfectly. I can control the temperature of the extruder in the manual mode and from the temperature CONTROL selection small screen on the machine. If I load the same file again it might work perfectly… Any ideas?

I am running MPCNC stock from Ryan - Marlin, Ramps, Repetier test file.
Standard hot end extruder and no end stops.

Any help would be appreciated.

It could be a usb issue, I would save the gcode onto your SD card, then run the file from the screen. Less chance for errors that way.

Thanks Ryan,
I have to get a SD card and give that a try. I found if I select MANUAL and select 220 degrees to preheat the extruder then slice the part and select print it works. I don’t know if there is a connection.

I reprinted the Z axis parts (new style) and replaced the roller to the new design. It eliminated the slant problem I was having and was able to get that axis to be straight up and down.

Thanks for your help.