820-00165

[2informaticos]

"swapped Q7630, no change"
No change what???
Post diode mode at PPBUS_G3H now.
You should get normal values, after changing Q7630.

"L7310 0.000 0.000
L7320 0.000 0.000"
I forgot them; if real, dead CPU more likely.

 

[Neil250]

OK sorry informaticos.
That was a stupid post.
Swapped Q7630.


PPBUS_G3H: 8.59V
DIODE MODE PPBUS_G3H: 2.86 V to GROUND
OHM MODE: 1.59 MOhm to ground



Checked all prior solder work

Plug in nothing, plug in again...nothing..plug in gain...fan spin...
Intermittent fan spin
Fan spin..stop..Fan spin--stop---> keeps going

Though it may be the DC in board--> swapped...intermittent fan spin
Though it may be the LIO cable--> swapped...intermittent fan spin

 

[2informaticos]

So 8.6V stable now at PPBUS_G3H?
Check if all voltages appear when fan spin.
Also try to start in SMC bypass mode.
Test the board alone on the desk, without any flex connected; nor LIO flex, just DCIN 5 pins cable.

 

[Neil250]

Voltage pulse on then off:

Board now only fan spins once then stops
If I plug the magsafe in and out it does it again:

Cannot start in SMC bypass mode.

Tested the board alone on the desk, without any flex connected; nor LIO flex, just DCIN 5 pins cable.

L7630: 1.05 V --> 0
L7620: 5.09 V
L7430:1.20V
L7560: 3.34V
L7750: 5.09V

THe coils pulse x 1

if it’s pulsing smc is good no?
cpu rail 0v

could this be a sensor issue?

 

[2informaticos]

Post U1950 voltage readings when fan spins.

 

[Neil250]

u1950 area is ugly on this board
bare pcb ground plane to the right on the pin 1/8 side of chip exposed

i think i have soldered and resoldered that chip 5 times

 

[2informaticos]

Pin 3 goes high when fan spins?

 

[Neil250]

Yes: 1.66V when fan spins

 

[2informaticos]

Fix the problem, MUST be 3V.

 

[Neil250]

Working on it.

REFLOWED U1950 again

Fan spins...4 sec..stop...spin...stop

U1950
1: ALL_SYS_PWRGD: 3.33V steady
2: 3.33V and steady

PIN 3: 0.25-0.30,1.60,0.25 -----> 2.5V diode mode to ground pin 3

Flip board over onto CPU side.
Fan now spins and stays spinning only to return to the start.stop.start stop pattern

Something is f'd up.
If PIN 2 is 3.33 V then the CPU is not dead correct?

 

[2informaticos]

You must get 3V at pins 5, 6, 3.