Macbook A1990 820-01041-A No Power on

[mon2]

Re: Macbook A1990 820-01041-A No Power on

The input voltage @ R7015 is too low. It should be 5 volts or higher.

Are you using the official and recommended power Type C adapter to power this logic board?

Start with the voltage to ground measurement of the port that is mated with the power adapter.

PP20V_USBC_XA_VBUS ; whichever is powering your board now
PP20V_USBC_XB_VBUS

You should see 5 volts going into your logic board.

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

i use the 96W original Apple. Pin 1 R7015= 4,15V

[mon2]

Re: Macbook A1990 820-01041-A No Power on

Ok. See attached. Measure the voltage at the entry fuses. It is possible that some component is pulling down this voltage.

If still the same 4,15V -> remove all power. Meter in resistance mode.

Measure the resistance to ground of R7015. What is the resistance reading ?

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

the board is hot at the point like in the picture from the cam. Maybe that's why only 4V?

[mon2]

Re: Macbook A1990 820-01041-A No Power on

Ok - proceed to remove the 2 x fuses in the last post = F3000 and F3001.

Then power up again and confirm that the adapter is indeed supplying 5 volts at the PCB pads of F3000 pin # 1.

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

F3001= 4,96V but F3000 is 0V But I see that the Q3100 is probably not ok. I think it was soldered! I took a picture. I think I have to swap it!

[mon2]

Re: Macbook A1990 820-01041-A No Power on

F3000 is linked to the other type C connector.

Move the power adapter to the other connector and confirm it.

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

I swapped Q3100 and I saw the cc742 was missing. Now it goes up to 20V and down again and sometimes 6V so unstable.

[mon2]

Re: Macbook A1990 820-01041-A No Power on

Does L7030 still get hot?

What is the voltage of ppbus_g3h with the fuse removed?

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

F7000 Pad 1 it's 5v it then goes up to 12v and then it goes back down to 5v and then it goes back up to 12v back and forth

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

L7030 is hot

[mon2]

Re: Macbook A1990 820-01041-A No Power on

Check if AWAKE and SLPS2R voltages are present; small coils surrounding U7800.

If any 0v, skip to test the next netname.

Post the readings.

Just saw the thermal.. wow.

Remove all power, check the resistance to ground of this coil.

[Strolch]

Re: Macbook A1990 820-01041-A No Power on

Awake 0,0015 V It also always goes on of 20V then 0

[mon2]

Re: Macbook A1990 820-01041-A No Power on

Remove all power -> what is the resistance to ground of L7030 ? It is getting hot due to some event in this region / power rail.

Is the fuse present on PPBUS_G3H output side ?