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  1. R

    820-00840 - Not booting

    Yes, got fed up with this one. Thanks for helping.
  2. R

    820-00840 - Not booting

    Fixed up major liquid damage near CPU FETS and Wifi/BT area. All voltages present, but not booting, no USB activity. Changed EFI. Dead CPU?
  3. R

    A1425 - Crashing under load

    Sorry, bumping my old thread. No odd temperatures (CPU ±80C when it crashes) reported. EFI ASD 155 won't run, I think this is caused more older macs because of a recent EFI update.
  4. R

    A1425 - Crashing under load

    This logic board keeps crashing, but only under load. Likely heat related? Any suggestions on this one, I'm not really familiar with this model.
  5. R

    820-3787 GPU crashes after drop

    Well, if it was my board this would be true. As it's the customer's board, I would like to be a bit less destructive. So again, any advice on how to safely reflow the GPU?
  6. R

    820-3787 GPU crashes after drop

    Would a reflow of the GPU be a viable option in this instance? And how would I do this without messing up the rest of the board?
  7. R

    820-3787 GPU crashes after drop

    Customer dropped this laptop and started having problems with the GPU ±3 months later. As a first attempt I've reflowed u9300, didn't help. Any suggestions on how to proceed?
  8. R

    820-3787 - Chime loop wich battery

    So, I've been struggling with this one over the last few days. * Replaced ISL > No change * Replaced SMC > Didn't work (possibly faulty SMC) * Replaced SMC with 3662 version and clean BIOS > Same behaviour (this one is just for testing, as I don't have any more 3787 donors) I'm guessing some...
  9. R

    820-3787 - Chime loop wich battery

    Measurement with batt connected w/o batt connected PPBUS_G3H 12.2 V rising to 12.7+ V 12.57 V steady SMC_DCIN_ISENSE 1.62 V 0.4 V SMC_DCIN_VSENSE 2.89 V 2.98 V SMC_CHGR_BMON_ISENSE 0.05 V 0.05 V Difference over R9398 (GPU Phase 2) 0 V >> 0 A draw 0 V Difference over R9399 (GPU Phase...
  10. R

    820-3787 - Chime loop wich battery

    Ok, I started testing for the suggestions above, but noticed the heatsink got hot real quick. Turns out phase 1 of the GPU is pulling ±35A from the start. GPU problem? I'm confused as to why that VR would even start at this point during POST/boot.
  11. R

    820-3787 - Chime loop wich battery

    According to the customer it just started doing this, no specific history.
  12. R

    820-3787 - Chime loop wich battery

    Yes, it starts on only the (known good) battery. Same behaviour.
  13. R

    820-3787 - Chime loop wich battery

    17/18: 3ohms 27/28: 20,9 ohms Known good battery tested, same behaviour.
  14. R

    820-3787 - Chime loop wich battery

    It won't let me do that, it starts instantly when I press the power button. Only thing I have left to try is corrupted BIOS maybe? Any other ideas?
  15. R

    820-3787 - Chime loop wich battery

    Assuming you mean safe mode (holding shift), same behaviour. Both current sense circuits measured fine when I replaced the ISL.
  16. R

    820-3787 - Chime loop wich battery

    This board works fully (in limp mode / 800MHz) when the battery is disconnected. When the battery is connected it chimes repeatedly, so at the end of the chime, it chimes again. A different battery produces the same result. Replaced ISL6259, didn't help. Any thoughts? Could this be GPU related?
  17. R

    820-00923 Critical update loop

    Although the area had some corrosion, traces seem fine. Not sure how to test whether the circuitry for the touch bar actually works. Any suggestions?
  18. R

    820-00923 Critical update loop

    Things tried so far: * Boot with wired connection * Boot with touchbar, touchID and screen disconnected * Full reinstall Will boot into safe mode. Had some corrosion on the touchbar side of the logic board.
  19. R

    My apologies for the downtime!

    Np, as long as we don't lose 320 pages of MacBook repair awesomeness :)
  20. R

    820-00875 Dead

    Ok, good to know. Not really up to speed on repairability of these "new" types. Thanks for your help guys, this is a no-fix.
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