Overcurrent Issue when connecting a display

[Ridddddd]

Hello, I am currently working with a STM32 development board that I am using to power (and code) a PCB that has an stm32 chip. So far, it has been working properly but I recently connected the PCB to a display (Newhaven display: LINK) and now the "overcurrent" LED is lighting up on the STM32 development board. Once I disconnect the display, it goes back to normal. Please refer to the pictures attached below. Additionally, please note that the display doesn't turn on and idk if it is due to the "overcurrent" issue. I am using a FFC Jumper cable and I'm pretty sure that it is connected properly. I am sending 3.3V to the PCB which should be fine.

Please help me as I am really confused.

 

With the display connected:

Without the display:

The display:

 

 

[mƎALLEm]

Hello @Ridddddd and welcome to the ST community,

Most probably the display you are adding to the board pulls more current that the board can generate especially due to the backlight of the LCD.

I propose to power supply the LCD with an external power source and ensure the common GND.

[EZHON.1]

it seems you are using the STLINK-V2-1, the current ask from the USB is 100mA at the beginning of the STLINK starting.  when you add the LCD, could you check the current consumption from LCD. if less than 500mA from LCD, you can use a pin to control LCD backlight or whole power to avoid the STLINK enumeration step.