My first DIY Prusa I3 Printer - Temperature issues

Dear all,
i hope to find my problem solution in this forum and thanks in advance for your support.
This is my first experience with Prusa I3 printer (MKS motherboard), so after completing to assembly and check that mechanical parts works very well, i made with success my first calibration.
In the warmup phase to prepare printer for loading PLA, when display showed temperature to 185°C, PLA didn't melt, so i checked with infrared thermometer and measured 86°C. For bed is the same, i measured 38°C when display showed 100°C; (I use Cura 15.02.1 for 3d Printing and Pronterface for loading PLA (1.76mm), below my Cura Settings :

Cura Basic Settings
Cura Advanced Settings
Cura Expert Settings
Cura Machine Settings


I tuned up temperature upto 260° and i measure about 130°C and PLA filament start to melt but i print only the base, then PLA stuck and i disassembled extruder to clean nozzle; I think that temperature showed to display with fahrenheit scale instead Celsius, isn't true?
Where am i doing wrong ? Can you help me ?
Below MKS motherboard connections, a Video and more pictures

Prusa I3 More Pictures


Thanks a lot in advance for your precious support.

Overclokkato

Edited 1 time(s). Last edit at 03/07/2015 02:32PM by overclokkato.

Hi
How do you measure the " about 130°C " ?

Hi,
i became suspicious and used infrared thermometer because PLA didn't melt

I did the same thing once, but the extruder is so small, I think the measure is far below reality. (in my case, it was)
To be sure, you can cut a piece of PLA and push (just with the hand) against the nozzle. (by the extérior)
You'll see if it melts.

Dear,
i try to adjust the orange screw to power supply and increase voltage from 12V to 14V, i saw few filament melt but cannot print again

Did you set the right thermistors in configuration.h?

I have MKS main board and use cura software.
I don't find configuration.h file.

What gforce1 meant is that you have to check your firmware (Marlin, Repetier, whatever) and check that the correct thermistors are selected in Configuration.h.

If you do not have the source code for the firmware you'll have to download it and recompile with the correct settings, using the Arduino IDE. If you do not know what I am talking about, take a few minutes to browse through the documentation in the RepRap.org wiki and become familiar with these matters.