MacBook retina 15" A1502 2012 - 820-3332-A

mapuceps2

New member
Dear friends

First, congratulations to Louis and his entire team.
Second, sorry, I don't speak English I use Google translation.

My problem.
Logic board A1502 Retina 820-3332-A
MagSafe light green / orange, ok.
The fans rotate at normal speed then slow down slightly then rotate normally, etc.
Watch this video:
https://www.youtube.com/watch?v=X869...ature=youtu.be
No dong, no display.
What should I check please?

Thanks for your help.

PS I did a complete reballing, no success
 

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

Reballed what?
For this board, ALWAYS start resoldering U8900 with leaded...
 

2informaticos

Administrator
Staff member
"PS I did a complete reballing"
Do you mean GPU reballed?

Post voltage on all big coils.
Do you get PLT_RESET_L?
 

mapuceps2

New member
Thank you for your help but I do not understand your request, I am not a super specialist.
All resistors, R2683, R2687, R2671, R2681, R2689 are good.
 

2informaticos

Administrator
Staff member
You said something about "complete reballing".
Does this mean GPU reballing?
Board could be now screwed up.

I didn't ask about resistors value.
Just measure PLT_RESET_L voltage.

"Post voltage on all big coils."
Like L7220/60, L7330 and more...
 

mapuceps2

New member
L7330 = 0
L7220 = 0
L7260 = 3.34
L3895 = 0
L7770 = 0
L7030 = 12.60
L9830 = 0
L8360 = 0
L8310 = 0
L7720 = 0
L7630 = 0
L7100 = 0
L8930 = 0
L8960 = 0
L7560 = 0
L7550 = 0
L7510 = 0
L7520 = 0
L7530 = 0

Reballing on U8000.
I did 16 reballing on 820-3332-B and all the logic boards worked again.

The orange magsafe but the computer not started.

Thank you very much
 

2informaticos

Administrator
Staff member
You expect video, but no voltages apart S5 ones...

No pulse at all on L7220, nor PM_SLP_S4_L?

Magsafe 2 85W charger for sure?
Check PM_BATLOW_L level.
 

mapuceps2

New member
I replaced Q5040 and R5041. No changes.
I recapitulate.
The fans start when the battery is connected and when I connect the MagSafe (60W)?
The fans are running well except that they slow down a little bit, a fraction of a second, and start up again and again without booting.
I can't turn off the fans using the keyboard, I have to unplug.
The fans do not start if the battery is not connected but it seems to me that this is normal.
It looks like the computer does not reach EFI.
Thanks for your help, it's nice but I don't want to monopolize your time.
 

2informaticos

Administrator
Staff member
"I connect the MagSafe (60W)
-----------------
fans do not start if the battery is not connected"
This board only starts with 85W charger, if battery not connected.

You've posted all coils 0V, apart of S5 state.
How then the board starts and fans spin???
 

mapuceps2

New member
Dear friend

Magsafe 85W received.
The keyboard reacted.
The MacBook starts up.
I have the startup dong.
No video or LCD + keyboard backlight.
Reset PRAM done.
I did a BGA reballing again, N13-GT-W-A2, still no video.
Serious progress but I don't know what to control for the video?
 
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