A2338 820-02020 No backlight

[loic2907]

Hi all,
I face a problem with this motherboard.
Working perfectly in HDMI.

First problem liquid damage.
Problems were on RD560 and RP800, these 12V with sense was dead.
And pin 9 on UC710 too.

RD560, RP800, UC710, UD560, UP800 has been replaced.

Now, on the screen (JP600) I have :

PP3V3_SW_LCD_CONN : 3V
EDP_PANEL_1V8_EN : 1.8V
PP5V_SW_LCD_CONN : 5V
PP5V_CAM : 5V
LPDP_INT_HPD : 0V
PPVOUT_LCDBKLT : 0V
I2C_BKLT_SDA : Have DATA with oscilloscope
I2C_BKLT_SCL : Have CLOCK with oscilloscope

On the UP800, pin 17 : BKLT_EN_R, I have 0V too.
I did a bridge on this pin, and I had PPVOUT_LCDBKLT : 50V.
No backlight visible on the screen with PPVOUT_LCDBKLT at 50V.

I tried my screen on another A2338, this screen seems to have lines but works perfectly.

Now, I'm short of ideas.
If some of you have a new one to help

[mon2]

Re: A2338 820-02020 No backlight

Backlight is a function of the LCD being detected and the lid sensor able to sense that the display is open.

Check the logic level of the lid status. This is from a hall effect sensor in the trackpad.

[mon2]

Re: A2338 820-02020 No backlight

Also 50v is too high for the backlight voltage. Be sure the backlight led strips are connected at the lcd display connector.

[loic2907]

Re: A2338 820-02020 No backlight

Backlight is a function of the LCD being detected and the lid sensor able to sense that the display is open.

Check the logic level of the lid status. This is from a hall effect sensor in the trackpad.

Hi thanks for you reply.
IPD_LID_OPEN_1V8 is 1.8V
Screen connected and close, in HDMI I have the log on the session if I open the screen, it desapear and print the background wallpaper only.
LID is working great so ?
For the 50V, the 2 connector on the board of the screen are connected too.

[5132857]

Re: A2338 820-02020 No backlight

Hi, I need the part number of the rd560 and where can I buy it? Thanks!

[jansmola89]

Hi. Did you found it somewhere? Is it possible to get RD560 from another one mainboard?I'd checked A1706, A1707, A1708, A1502 mainboards but no luck there