JCE
New member
Dear all,
I have an 820-00923 A1706 Touchbar MacBookPro, which had a minor liquid damage. CB300 was corroded which I was able to replace thanks to Louis' video! THX for that!
• PPBUS_G3H = 13V
Now I am stuck. The backlight works, I have fanspin (but only if I do not attach the trackpad connector), but no image on the screen nor on the touchbar. The only image I saw once was the red "battery-low" image, so the screen works in principle. I tried to attach an external screen, but no luck with that either. Current drawn at 20V changes goes up to 0.9A and then changes between 0.4A and 0.6A. But no sign of boot.
• PPVCC_S0_CPU is between 0.64V and 1.2V which seems to be OK
• PP3V3_S4_TPAD = 3.3V (with and without trackpad, so no shortcut on power line from trackpad)
But:
• PPVCCGT_S0_CPU = 0V (Graphic cores of CPU do not get any power), but there is/was no corrosion around these chips (U7410, U7420, U7430)
• PPVCCEDRAM_S0_CPU = 0V (not OK)
• PPVCCEDRAM_S0_REG_F = 1.05V (OK)
Questions:
• Any clue why connecting the Trackpad (being optically in perfect condition, no corrosion or signs of liquid) prevents fans to spin?
• Is it normal that PPVCCGT_S0_CPU has 0V in early boot stage?
• Any clue on how to proceed?
Attached is a movie of the power drawn during boot:
Kind regards,
Jean-Claude
I have an 820-00923 A1706 Touchbar MacBookPro, which had a minor liquid damage. CB300 was corroded which I was able to replace thanks to Louis' video! THX for that!
• PPBUS_G3H = 13V
Now I am stuck. The backlight works, I have fanspin (but only if I do not attach the trackpad connector), but no image on the screen nor on the touchbar. The only image I saw once was the red "battery-low" image, so the screen works in principle. I tried to attach an external screen, but no luck with that either. Current drawn at 20V changes goes up to 0.9A and then changes between 0.4A and 0.6A. But no sign of boot.
• PPVCC_S0_CPU is between 0.64V and 1.2V which seems to be OK
• PP3V3_S4_TPAD = 3.3V (with and without trackpad, so no shortcut on power line from trackpad)
But:
• PPVCCGT_S0_CPU = 0V (Graphic cores of CPU do not get any power), but there is/was no corrosion around these chips (U7410, U7420, U7430)
• PPVCCEDRAM_S0_CPU = 0V (not OK)
• PPVCCEDRAM_S0_REG_F = 1.05V (OK)
Questions:
• Any clue why connecting the Trackpad (being optically in perfect condition, no corrosion or signs of liquid) prevents fans to spin?
• Is it normal that PPVCCGT_S0_CPU has 0V in early boot stage?
• Any clue on how to proceed?
Attached is a movie of the power drawn during boot:
Kind regards,
Jean-Claude
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