Turning on hotend disconnects printer

[htp]

I have a Prusa i3 M201 with the GTM32 Pro B board, and I am encountering an issue where when I set the temperature and turn on the hotend (heat the extruder) the printer disconnects. The display on the printer flashes/"blinks" and then I must reset the printer. This issue persists regardless of the software being used.

I am using two extruders/hotends, and I have not made any modifications to the board/printer itself. I suspect that the voltage output may not be correct, or that the power supply is faulty. However, I am unsure of the true issue as this problem has just manifested without any change to the system.

Currently, I will take a look at the connections to the board; perhaps there is a bad connection. However, I would deeply appreciate any help or advice.

Also: Is there a schematic of the board available? I would like to understand the connections better.

[William]

Here is the schematic of the GTM32 Pro B board, best wish to you.