820-3115-B Macbook Pro no charger light

[LCDR2]

Macbook Pro

First look at the computer... Able to Power on the computer. No "bong", Red Charge Light (after about a minute) and full fan spin.

Now .. well something else has gone wrong. Now no light on the charger and 11.2v at PPBUS_G3H (battery connected) 0v W/O battery.

I don't think I "did" anything... but must have shorted something I guess ?

Sigh..

Where to start oh wise ones?

 

[2informaticos]

Start disconnecting battery.
Do not reconnect it until get correct PPBUS_G3H voltage.

Do you get 3V42_G3H at least?
Post ohm values for R7080/81 and R7085/86, measured onboard.

 

[LCDR2]

HI,
I got very little anywhere.
I have replaced the DC in jack (820 - 2565) with a known good which seems to have helped a bit.

I was working my way through power rails and related circuits (as I guess / assume they're related) so apologies if some of these are out of order or unnecessary.


PPVIN _G3h_P3v42G3H (mesured at D6990) 18.09v
3V42_G3H - 149.2 mv
PPBUS_G3H 30.5mv
PPCHGR_DCIN_D 18.5v
CHGR_PHASE 10.5mv

So based on this I would conclude that there is something wrong with the circuit that is creating PPBUS_G3H

At this stage I believe I have power going INTO U7000 via PPCHGR_DCIN_D (@R7005). but not OUT of u7000.

I see on pin 24 of U7000 there is CHGR UGATE but I am not sure if that functions as a enable or similar circuit.

My backtracking lead me to the schematic page which has R7080! So hopefully that means I am on the right track!

R7080 - 99.9k (good I think)
R7081 - 60.7 (good too)

R7085 - winner winner ? 0.577m Ohms
R7086 - 307K

.......


So replace R7085 which would fix CHGR_AGATE which makes CHGR_Phase work?

I shall await your response.

Cheers

James

 

[2informaticos]

"R7085 - winner winner ? 0.577m Ohms"
m stands from mili, but I bet you meant Mega; confirm please.
Reading should be closer to 470K (0.47M).
However, doesn't look like Mosfet leakage.

Post diode mode to ground at L6995 and F7040.

We need some voltages for U7000 too; pins 1, 2, 3, 9, 15, 17, 19, 20, 27.
Also post exact resistance (ohm mode) between its pins 17/18 and 27/28.

 

[LCDR2]

Hi 2informatios

Diode mode I get
L6995 0.108 _G3H on one side and 0.0 on the other (_SW)
F7040 0.413


U7000

17 / 18- 3.2 Ohms (measured at R7051 and R7052 because my micro multi meter probes are not here and they appear to be connected)
27 / 28 - 20 Ohms (similar measurement style)

U7000 Voltages


1- 17.8v
2 - 18 v
3 - 8 mv
9 - 32.3mv
15 - (negative 160mv)
17 - 4.5mv
19 - 5.08v
20 - 5.08v
27 - 2.7mv

 

[2informaticos]

"3 - 8 mv"
Bad enough.

First post diode mode to ground there.
If low, remove C7011 and check again.
If still low, change U7000.
If no short, replace R7010.

"L6995 0.108 _G3H on one side and 0.0 on the other (_SW)"
I'm not really sure about this; do you mean L6995 is broken/open and short to ground before it??

 

[LCDR2]

7 - 7.68 M ohms
replaced suggested. Will repost after I US all the flux away