MacBook A1989 - no power 5V 0.05A

[tommy97]

Hi guys i've got A1989 with no power, draw 0.05A with 5v, checked PPBUS_G3H 12.28V, PP3V3_G3H 3.3V, there is no corrosion neither liquid damage. Exactly same reading on each port/each side. I don't have schematics near my however on the 2.7v SSD coils I had reading of 140Ohm's is that normal or failed SSD?

No short find, with and without battery, same reading.

[mon2]

Ppbus_g3h is too low. Check the voltage to ground of the smbus lines on the battery connector (SDA & SCL).

[tommy97]

Both SMBUS Lines are 3.3v
PPDCIN_G3H_CHGR 5V to the ISL

[mon2]

SMBUS lines are not shorted. Ok. But PD controllers are not negotiating the boost voltage of 20v from the PD power adapter. The ISL (U7000) is operating in boost mode, not buck mode (20v to PPBUS_G3H voltage).

Focus on the CD321x controllers and the article by piernov and others on how 20v is selected. Review the LDO rail on each ACE controller to be sure one is not defective.

https://logi.wiki/index.php/CD3215_Bootup_Sequence

[tommy97]

Readings on each port
PP3V3_UPC_XB_LDO 3.3V
PP1V8_UPC_XB_LDOA 1.8v
PP1V8_UPC_XB_LDOD 1.8V
PP1V1_UPC_XB_LDO_BMC 1.1V
HV_GATE1/2 (couldn't find on this board)
PPDCIN_G3H 5v
PPCHGR_VDDA 5V
PM_EN_P3V3_G3H (couldn't find on this board)
PP3V3_G3H - 3.3v
PP1V2_G3H_SMC_VDDC (couldn't find on this board)
USBC_XB_CC1 1.75v

[mon2]

Remove all power. Meter in resistance mode. Measure the resistance to ground of each inductor. Check if each power rail is without a short.

Test with a dfu process.

[tommy97]

Laptop was in DFU, after revive laptop works however is extremely slow, battery fully charge, touchbar keyboard trackpad are working.

[Palafox]

Did you ever find out what was causing the mac to be so slow? I'm have a similar issue

[mon2]

If a mac is running slow, confirm the OS is not to blame. The logic board may be unable to ping one or more of the sensors and then the CPU speed will be throttled for safety. There are such sensors inside of the trackpad and is a common fault. Any spills on the keyboard / trackpad? Review the cabling in this area. Replacement trackpads and cables should be available on Amazon or Mobile Sentrix. For extreme cases, the bios may need to be reflashed if corrupt but your unit is booting so review the other issues. You can run a diagnostic to check on the error code leading to this hauldown of the CPU speed.

What is the history? If the power adapter is under rated, the CPU will also be throttled and the battery charging will halt. Confirm the external power adapter.

[tommy97]

All components were good as on the new motherboard it works fine, i finally replaced motherboard as i needed data of the device however to transfer 100GB it took 2days.