A2338 820-02020 No backlight

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • loic2907
    Member
    • Feb 2020
    • 31
    • France
    #1

    A2338 820-02020 No backlight

    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
    Attached Files
    Last edited by loic2907; 03-07-2023, 03:10 AM.
    Tags: None
    • mon2
      Badcaps Legend
      • Dec 2019
      • 14086
      • Canada
      #2
      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.

        Comment

        • mon2
          Badcaps Legend
          • Dec 2019
          • 14086
          • Canada
          #3
          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.

            Comment

            • loic2907
              Member
              • Feb 2020
              • 31
              • France
              #4
              Re: A2338 820-02020 No backlight

              Originally posted by mon2
              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.

                Comment

                • 5132857
                  New Member
                  • Jun 2023
                  • 1
                  • canada
                  #5
                  Re: A2338 820-02020 No backlight

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

                    Comment

                    • jansmola89
                      #5.1
                      jansmola89 commented
                      12-04-2023, 09:41 AM
                      Editing a comment
                      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
                    Previous template Next

                    Related Topics

                    Collapse
                    • Timp74
                      820-02100/02098 LCD Backlight Controller IC UP800..
                      by Timp74
                      Hi All.

                      Does anyone know if Macbooks will power on without their display backlight controller ICs? Explicitly I have an a2485(very similar to a2442) that has the UP800 IC broken/missing. On attaching a USB PD charger it stays at 5v ~1A for 20 seconds and then resets and repeats the cycle.

                      The history is that the machine was water damaged to IC UP800. A Renesas 209100b1 Buck Boost controller. The machine still worked, but without the display backlight coming on. UP800 wasn't generating any switching signals to the four driver mosfets. I removed UP800 and check the...
                      11-25-2022, 11:57 AM
                    • todordm
                      Macbook A2338 / A2337 - Replace SSD
                      by todordm
                      There are a lot of Video Tutorials how the SSD of A2338 or A2337 can be upgraded. Normally they say you can order the bigger SSD chips (0 and 1) from China. But as far as I understand you can take the SSD chips of one A2337/A2338 and install on another, put to DFU mode, do the recovery, reinstall etc... I tried that several times (tried to upgrade 256GB to 512Gb, then to 1TB, then to another 256Gb)... nothing worked. So my question to the community is: can I just take the SSD chips from one A2338 and intall them on another A2338 (taking care of course of the 0 and 1 positions)? Or I have always...
                      01-17-2024, 03:55 AM
                    • User555111
                      A2338 13" 2022 MacBook Pro M2 820-02773 Touchpad/Keyboard/Display not working
                      by User555111
                      Currently Im trying to get this A2338 13" 2022 MacBook Pro M2 to function properly, Right now the trackpad and keyboard are not working but the power button and keyboard backlight are working. the Touch Bar shows display but does not respond to touch. I bought it on eBay and it was described as having a bad lcd. When I received it however I found that it was also missing the wifi and bluetooth antenna along with most of the screws hardware. it was also showing picture on the LCD but no backlight, I could also see some lines on the screen indicating the lcd was also somewhat damaged. on top...
                      02-05-2024, 08:16 AM
                    • jkruns
                      Macbook Pro M1 A2338 - how to test for 20V?
                      by jkruns
                      I have a stack of liquid damaged A2338's, most of which don't draw more than 5v and thus won't turn on.
                      So far I've put back the main boards back after cleaning and repair attempts and connected every single component before testing. This obviously take a huge amount of time.

                      My question is (maybe not limited to A2338 boards): what's the bare minimum that needs to be connected in order to test if it will draw 20V? Should it draw 20V without the battery connected?
                      10-18-2024, 10:38 AM
                    • jkruns
                      M1 A2338 screen and touchbar issues after cleaning up liquid damage
                      by jkruns
                      Hello everyone,

                      This is my first post after browsing this wonderful treasure trove of knowledge for many, many evenings. I've decided to learn how to fix these things, properly.

                      My patient is an A2338 Macbook Pro M1 (late 2020).

                      It had some corrosion around JT710 and JT700 caused by liquid spill, as well as against the protective barrier around the USB-C chips UF000 and UF100. So I took the main board out and cleaned it with a toothbrush and alcohol, then with alcohol in an ultrasonic cleaner. Cleaned the touchbar flex connectors as well. The board looks...
                      04-22-2024, 06:45 AM
                    • Loading...
                    • No more items.
                    Working...