[SOLVED]820-3332-A No back light, Video yes.

[Dewanbd]

820-3332-A No back light, Video yes.
- BKLT_EN_L - 0V
- BKLT_EN_DIV - 12.2v
- F9700 is fine and has 12.6V on both sides
- PPBUS_SW_BKLT - 0v
- BKLT_EN - 0v
- 5V_S0 not present
- D9701 Pin 1: 0v
- D9701 Pin 2: 0v
- Pin 1 of LCD connector has 0v
- R9753 and R9757 are both good and have continuity to U9701
- BKL_SW - 0v
- BKL_FB - 0v

 

[aprendiz]

Voltage on LCD_BKLT_EN and BKLT_PLT_RST_L??

 

[Dewanbd]

both are 0V

 

[dukefawks]

That seems very unlikely. Did you measure those with an LCD connected?

 

[Dewanbd]

both are 0V . no LCD connected. Thanks.​

 

[Dewanbd]

with LCD connected

LCD_BKLT_EN is ​

0V​

and BKLT_PLT_RST_L is ​

3V.​

 

[aprendiz]

The display is tested working? Do you have other display to test???

 

[Dewanbd]

I don't have other display.

 

[dukefawks]

with LCD connected
LCD_BKLT_EN is
0V
and BKLT_PLT_RST_L is
3V.

PLT_RST has always been high, there is no way for the board to boot without that being present. That means your measurements were not correct.

Are you 100% sure there is video on the LCD? Check if SMC_LID is high.

 

[Dewanbd]

my display has liquid damage , power cable burn , jump the wire and now working. Thanks for helping.