Search results

  1. S

    820-00928 A1707 2017 board with 20A but 0A

    I have a 820-00281 board that came in with liquid damage and completely unresponsive. After removing a capacitor that had shorted PPBUS_HS_CPU to ground and replacing all four CD3215, I now get 20V on USB-C but 0A. PPBUS_G3H: 12.6V PP3V3_G3H: 3.3V PP3V3_PMICLDO = 3.3V PP1V25_PMICVREF = 1.24V...
  2. S

    820-02016 A2337 Air board with fluctuating voltages

    This 820-02016 board was a test board in a shop and abruptly stopped working during the testing of some bad audio boards. USB-C is at 5V, PPBUS is 12.3V, and PP3V8AON is 3.8V. Many secondary rails are fluctuating between 0 and their expected values, about every 1/2 sec. This includes PP1V25_S2...
  3. S

    820-01700 board without DFU mode

    This 2019 16" Pro board supposedly "randomly stopped working". USB-C is stuck at 5V unless I connect a fully charged battery (20V 0A then). PPBUS is 12.3V and it is missing PP3V3_G3S_T and P3V3G3S_EN. The keyboard method for getting into DFU mode results in SOC_FORCE_DFU to go to 1.8V and stay...
  4. S

    820-01987 2020 MacBook Pro with liquid damage

    This 820-01987 board had light liquid damage in the area near U7420, one of the CPU FETs, and some other minor spots. I replaced several corroded components, including U7420. The machine shows a clicking trackpad and some activity on the fan, but no startup. I'm now trying to determine whether...
  5. S

    Unresponsive A2337 MacBook Air 820-02016

    This A2337 M1 Air shows no obvious logic board damage but is unresponsive. Without a battery connected, USB-C goes to 20V, then goes blank, then cycles. PPBUS_AON cycles between 12.0 and 12.3V. With a good battery connected, PPBUS_AON is steady at 12.55V. Trackpad clicks intermittently. DFU...
  6. S

    820-01598 A2159 board missing Wifi and Bluetooth

    This board came in without liquid damage, but with a missing screen backlight and non-sensitive Touch Bar. I found two burnt & melted inductors (L5100 and L8504) and a burnt via near U8500. Fixing those issues restored the backlight and Touch Bar. But the board is missing Wifi and Bluetooth (no...
  7. S

    820-01598 A2159 with startup issues

    This 2019 Pro behaves in a way I have not seen before. It initially started up to a circle with a line through it. I performed a DFU Restore, which completed successfully (padlock). Now, when I startup using Internet Recovery, the machine gets part way through startup, then the fan blows hard...
  8. S

    MacBook Pro 820-01949 2020 with no internal display

    This A2251 MacBook Pro with mild liquid damage (USB-C area) is working fine on external display but does not recognize the internal LCD. I tried several displays and flex cables, and there is no backlight and no display. The internal does not show up in Settings>Displays, only the camera is...
  9. S

    820-01958 board with keyboard backlight issue

    This board from an Air A2179 arrived with liquid damage and PPVOUT_S0_LCDBKLT shorted to ground. After replacing several corroded capacitors, the short was removed, and the machine started up with the LCD backlight fully functional. Initially, the keyboard backlight appeared functional as well...
  10. S

    MacBook Air A2179 with Internet Recovery failure

    This 2020 MacBook Air (820-01958) shows no signs of damage other than a bad battery, which I replaced. It loads Internet Recovery very slowly and, after 20 minutes, always ends with error -2003F. It fails to enter DFU mode (both keyboard method and using FORCE_DFU pins). So I removed and...
  11. S

    Chasing down a 100Ω short to ground in 820-01521-A

    This 820-01521 2019 Air board had liquid damage in several places, was missing PPBUS, and had shorts on both CD3215s. I replaced all corroded components I could find, including both CD3215s. Now I'm left with PP5V_G3S which shows 80-100 Ω to ground (0.07 in reverse diode mode). No shorts on any...
  12. S

    820-00850 2019 Pro A1989 with display backlight issue

    MacBook arrived with no screen backlight and liquid damage in the backlight circuitry around U8400. Replaced all corroded components, including U8400. Now the backlight works but only when I select a very low brightness setting. It disappears when the brightness setting is raised...
  13. S

    820-01521 MacBook Air 2018 with USB-C issues

    This 2018 Air came in with liquid damage in the area of the USB-C connector on the logic board. Pins 59 (20V) and 55 (Gnd) on the connector were visibly burnt, and a few nearby caps looked corroded (C6405, C6416, CC711, C3306). After clean-up, USB is now stuck at 5V, drawing 0.08A. PPBUS is at...
  14. S

    M1 MacBook Pro A2338 2020 820-02020 stuck in a boot loop

    This 820-02020 had some minor liquid damage in the areas of UR630 (speaker amp), UD540 and UD560 (PP3V3). It is stuck in a boot loop: it chimes, then begins to show the progress bar to around 15-20%, then shuts down and chimes again. This happens with every connector unplugged from the logic...
  15. S

    820-01521 board with MDM issue (2019 MacBook Air)

    I have a 2019 820-01521 board that is MDM (Remote Management) locked due to the previous user's neglect to remove it from the MDM server. What is the best way to return the board to a normal state? I assume it involves reflashing the SoC ROM, as well as replacing the NAND modules?
  16. S

    820-00850-A without startup (A1989 MacBook Pro 2019)

    This 820-00850 board shows no discernible liquid damage but has an unknown history. The trackpad clicks, fans spin, but nothing else happens. DFU Restore was successful, with Apple logo and progress bar on target machine and padlock on host machine. I have PPBUS 12.6V, PP3V3_G3H, PP5V_G3S, all...
  17. S

    Liquid-damaged 820-00165 (Air 2017) with updating issues

    I'm trying to revive an old 820-00165 board with liquid damage. I replaced several corroded components around U1950, U5000, U7701, and U6100, including the SMC, backlight driver, and EFI chip. Now this machine is running nicely and passes Apple Hardware Test. But whenever I try to update the OS...
  18. S

    2020 M1 MacBook Air 820-02016 with startup issues

    This A2337 Air came in "water-damaged", but the only evidence of liquid exposure was on the USB-C plugs, which were badly corroded. With a fresh USB-C board, the machine chimes but only shows a blank screen (backlight is on). On an external display, the screen flashes on and off, showing the...
  19. S

    820-01521 2018 Air with missing VCORE

    I'm working on a 820-01521-A board that had liquid damage and corrosion in the CPU VCCSA circuitry. I replaced a visibly burnt FET driver for PPVCCSA_S0_CPU (Q7291) and several components around it. This restored PPVCCSA_S0_CPU to the expected 0.8-1.1V. However, I'm missing CPU VORE...
  20. S

    Looking for the SoC ROM for 820-01521-A

    I'm looking to reflash the SoC ROM chip (U4770) on a 820-01521 (2019 MacBook Air). Does anyone have a known-good bin file?
Top