A1502 820-4924-a

zcinciev

New member
Hi Guys.

A1502 green light no power. Had liquid damage on keyboard connector contacts 10-15 cleaned it renewed the contacts. i noticed while measuring PPBUS_G3H and L7130 Beeps :D

Any advice...:)
 

JohnB8812

New member
Are you measuring without the keyboard and trackpad and battery attached? Voltage on PPBUS_G3H? Does VCore pulse at all?
 

2informaticos

Administrator
Staff member
Exact PPBUS_g3H voltage, without battery connected?
Does the board starts by itself if disconnected TP/KB?

"PPBUS_G3H and L7130 Beeps"
Why not?
That confirm at least F7140 is OK.

Are you using original 60/85W Magsafe 2 charger?
Do you get 3V3_S5/SUS?
 

zcinciev

New member
Good Morning :)

Measuring without keyboard attached

PPBUS_G3H
R7005 pin1 16.44v pin2 16.57v
F7140 12.59v

PP3V3_SUS no voltage
PP3V3_S5 no voltage

PP5V_S5 5v
 

zcinciev

New member
Short on C7870 and all around that line...

U7501
Pin 12 - 3.4v
Pin 13 - 2v
Pin 21 -3.4v
Pin 22 - 3.29v
Pin 23 - 12.59v
Pin 29 - 5.04v
 

2informaticos

Administrator
Staff member
You should get 3V3_S5 on L7560.

"Short on C7870"
But you need to eliminate the short first.
Lift pin1/L7560 and see which side the short remains.
 

zcinciev

New member
Short on PP3V3_S5 side no voltage on L7560.

Looking for any other corrosion liquid damage but everything seems clean
 

2informaticos

Administrator
Staff member
So you have short on pad1/l7560, not on pad2.
What is the exact value, ohm scale?
You can try injecting voltage; let see if something heats up.
Start with 1V and go up, no more than 5.5V, maintaining bellow ampers limit of power supply.
 
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