Macbook Pro A1708 2017 5v 0amp draw

[platinumsteel]

Hi guys i have a 820-00840 board here according to my USB C amp meter showing 5 volts and 0amp draw. I have PP3v3_G3H present on output of U6990 on UL6995 Coil. Also have enable from U7000 PM_EN_P3V3_G3H on pin 10 of U6990. On both CD32's the big caps close to it I got PP3v3_G3H present. On PPBUS_G3H diode mode 0.313v and Resistance is 1.549K around there.No corrosion on the board no history. is it possible it might have a dead SMC ? hoping you guys can maybe help point me in the right direction or have me check anything i missed. Thx

[mon2]

Re: Macbook Pro A1708 2017 5v 0amp draw

What is the voltage to ground of PPBUS_G3H?

What are voltage to ground measurements of the SMBUS interface lines (SCL and SDA) used by this ISL regulator (U7000)?

[platinumsteel]

Re: Macbook Pro A1708 2017 5v 0amp draw

What is the voltage to ground of PPBUS_G3H?

What are voltage to ground measurements of the SMBUS interface lines (SCL and SDA) used by this ISL regulator (U7000)?

Hi PPBUS_G3H = 0v
SMBUS_SMC_5_G3H_SDA = 3.4v
SMBUS_SMC_5_G3H_SCL = 3.4v

[mon2]

Re: Macbook Pro A1708 2017 5v 0amp draw

Remove fuse F7000. Power up again and check the voltage to ground of PPBUS_G3H.

If still 0 volts, remove all power.

Meter in diode mode.

Red meter probe to ground.
Black meter probe to F7000 pad #1. Reading?

Repeat with F7000 pad #2. Reading?

[platinumsteel]

Re: Macbook Pro A1708 2017 5v 0amp draw

Remove fuse F7000. Power up again and check the voltage to ground of PPBUS_G3H.

If still 0 volts, remove all power.

Meter in diode mode.

Red meter probe to ground.
Black meter probe to F7000 pad #1. Reading?

Repeat with F7000 pad #2. Reading?

Okay voltage on PPBUS_G3H = 0v
Diode Readings :
F7000 Pad 1 = 0.545v
F7000 Pad 2 = 0.312v

[mon2]

Re: Macbook Pro A1708 2017 5v 0amp draw

What is the voltage to ground of SMC_RESET_L ?

[platinumsteel]

Re: Macbook Pro A1708 2017 5v 0amp draw

What is the voltage to ground of SMC_RESET_L ?

SMC_Reset_L = 3.4v

[mon2]

Re: Macbook Pro A1708 2017 5v 0amp draw

U7000 is a suspect. Post pics of this area.

What is the voltage in to this buck boost regulator?

Confirm the resistance of the current loop circuits on this regulator without power to the board.

The resistance checks must match the schematic values.

Is the SMC area clean and without corrosion ?

[platinumsteel]

Re: Macbook Pro A1708 2017 5v 0amp draw

U7000 is a suspect. Post pics of this area.

What is the voltage in to this buck boost regulator?

Confirm the resistance of the current loop circuits on this regulator without power to the board.

The resistance checks must match the schematic values.

Is the SMC area clean and without corrosion ?

I think you are right about it being U7000 as the suspect. It was working fine then a few days ago I had previously removed it and borrowed it to resurrect and troubleshoot 2 other boards i had.So maybe the other board may have killed it . Or it finally died because of all that hot air from removing and reballing and stuff.I will order some replacement ones and i'll report back if successful. thanks again mon

[platinumsteel]

Re: Macbook Pro A1708 2017 5v 0amp draw

Hi mon I just thought i'd report back.It was indeed the SMC.Looks like it was a bad SMC.I changed the SMC and it started back working again as normal. 20v and taking amps .And i have picture. Thanks again for the help.