Arduino pin gets high when shield is attached

Hello all,

I have an Arduino Mega2560 to build 3D printer. I have the code below for testing pins

void setup ()  {
#define X_ENABLE_PIN       38
#define Y_ENABLE_PIN       56
#define Z_ENABLE_PIN       62
#define e0_ENABLE_PIN       24
#define e1_ENABLE_PIN       30

pinMode(X_ENABLE_PIN, OUTPUT );
pinMode(Y_ENABLE_PIN, OUTPUT );
pinMode(Z_ENABLE_PIN, OUTPUT );
pinMode(e0_ENABLE_PIN, OUTPUT );
pinMode(e1_ENABLE_PIN, OUTPUT );

}

void loop (){
  
digitalWrite(X_ENABLE_PIN,LOW);
digitalWrite(Y_ENABLE_PIN,LOW);
digitalWrite(Z_ENABLE_PIN,LOW);
digitalWrite(e0_ENABLE_PIN,LOW);
digitalWrite(e1_ENABLE_PIN,LOW);


}

When I measure pin 38 with a multimeter, it seem low inherently. But when I attach shield, it becomes high. I checked all of the short circuits on the shield.

On the board, the schematic is like below.

What could be the problem

What problem ?

It is unlikely there is any problem in what you describe. Most enable pins are active in a LOW state. That means you need to pull it to a LOW level to activate that function. The chip will have an internal (or maybe some external) pull up resistor, so that when it is not controlled, that !enable signal will not be controlled by accident.

MAS3: What problem ?

It is unlikely there is any problem in what you describe. Most enable pins are active in a LOW state. That means you need to pull it to a LOW level to activate that function.

He is pulling it low, but it's staying high. To me? That's a serious problem with the shield...

(or his multimeter)