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

 

[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