820-02020 M1 Displays on external but No internal image

[huzeafa]

Good day guys, I have an M1 board, that does not display on the internal screen, No image or backlight, but I get display on an external screen. The board is clean, I have tested with a different screen but no changes, I tested the original screen with another board, and it displays.

PP3V3_SW_LCD_CONN= 3.3V
PP5V_SW_LCD_CONN= 5V
EDP_PANEL_1V8_EN= 1.8V
LPDP_INT_HPD= 0V
I2C_MLB2JERRY_3V3_SCL= 3.3V
I2C_MLB2JERRY_3V3_SDA= 3.3V
I2C_ALS_1V8_SCL= 1.8V
I2C_ALS_1V8_SDA= 1.8V


PLEASE HELP ME WITH WHAT NEXT TO DO/CHECK.

 

[2informaticos]

"LPDP_INT_HPD= 0V"
M1 expects high voltage, in order to enable internal video.
Did you change the small video cable too?

 

[huzeafa]

YES I CHANGED IT , NO CHANGES ,

"LPDP_INT_HPD= WHAT DO I NEED TO GET THIS SIGNAL HIGH?

 

[2informaticos]

This signal comes from LCD assembly.
M1 may have an internal damage and pulls down the signal.
Compare diode mode readings on JP600 lines with good board; w/ and w/o LCD connected.

 

[huzeafa]

Ok thank you