MacBook Pro 15" 2012 dead

[e.salmus]

Hi folks!

I have an issue with MacBook Pro 15, mid-2012. For now, it is dead. It didn't get any liquid or fallings, just died in my arms.
My problems started like that:
When I connected charger then it didn't charge. No lights on Magsafe but remained working on battery.
Then I checked my charger on another MBP and it worked. I tried other charger on my MBP and still no lights on Magsafe nor charging.
Several minutes went by and MBP just died. Can't turn on and no activity.
I disassembled laptop and took out motherboard to start tracing the fault. I tried to turn it on from keyboard connector but no luck.
I measured magsafe board while connected to motherboard and charger present. I get 0.9V from charger connectors and 0.3V from center pin. I tried to "brute force" charger to turn on by adding a 4k7 resistor to 1. and 2. pin on magsafe board. Then I hear weak "sine tone" from somewhere on motherboard and I get around 3V reading from magsafe pins 1 and 2 but still no lights on magsafe. Conclusion:
1: something drains power drastically
2: why computer doesn't let charger to turn on?

I have read numerous topics on MBP 13 issues but I lack finding any clues on so new MBP...

Does anyone have any ideas what to measure?

I would appreciate if someone could give me datasheet for my MBP or schematics for magsafe onewire system and power distribution system.

[dellxps15]

Re: MacBook Pro 15" 2012 dead

macbook have a smc chip that tell magsafe that only if all voltaged are ok it let magsafe voltage to come.... dont put resistor or try to bypass macbook that way. check main fuse and misure if 16 18.5volt are present. try power it on iwth a charged battery.

[ktmmotocross]

Re: MacBook Pro 15" 2012 dead

check "geohot" ic. it generates 3.42V and "boost" voltage. it regulate the charger

[techman1025]

Re: MacBook Pro 15" 2012 dead

Hi First by pass the SMC hold power button down and then plug adapter in let finger's off power button ...then press power button see if it start.
Techman1025

[e.salmus]

Re: MacBook Pro 15" 2012 dead

Thank you for reply.
Somehow today laptop powered on from battery but still no charging and no magsafe LED lights.
Fortunately I managed to measure voltage. Why I think magsafe is not powered on is because when there is no charger present then there is 9.82V on pins 1 and 2 on magsafe board. Center pin, 3. pin, has no voltage measured across ground. When I connect charger then I get 9.75V on pins 1 and 2. And i get 8.46V on pin 3 to ground. I think on 3. pin there has to be a lot less voltage

Any more advice?

[ktmmotocross]

Re: MacBook Pro 15" 2012 dead

check voltage output from geohot ic

[e.salmus]

Re: MacBook Pro 15" 2012 dead

It is hard to find that geohot ic. Please give me ideas, what it looks like, IC number? Do you mea G3hot IC?

Edit: I found that IC 625.
I measured with and without charger and battery present while computer turnd off.
Fom pin 1 I got 9.48 to ground
on pin 2 I got 9.87V to ground
On pin 3 I got 2.4V to ground

I think that chip has a problem

[dellxps15]

Re: MacBook Pro 15" 2012 dead

pin 1 must be 0 volt if all ok. pin 2 must me something around 16 volt

pin3 dont remember, pin 4 should be 4 volt and so on. some chip become hot ?

[e.salmus]

Re: MacBook Pro 15" 2012 dead

I noticed that there is 62882C what has same voltage on it as 625. That 62882C goes somwhat hot while laptop is powered on. I would say over 70 degree Celsius because I can't hold my finger on it.

[e.salmus]

Re: MacBook Pro 15" 2012 dead

Small update.
I replaced IC 625 but voltages are same.
I disconnected battery and magsafe green light started to glow very dim and I get around 16V on main capacitor near that chip. I will do more measurements on that IC 625.

[ktmmotocross]

Re: MacBook Pro 15" 2012 dead

this is geohot ic
https://cdn.badcaps-static.com/pdfs/...af8374970d.pdf

[e.salmus]

Re: MacBook Pro 15" 2012 dead

I am running out of any ideas. Now Macbook is not powering on again, magsafe green light is very dim (it does not matter if battery is present or not). I did some measurements but it is quite hard to think of anything without proper schematics. I have A1278 820-3115 schematics and from there I have done some conclusions.
I think I found that geohot ic but i got 0V reading on any of those pins.

Please help me and ask for more measurements on certain points on the picture.

[mohamed.mostafa]

Re: MacBook Pro 15" 2012 dead

have you tried a "copy mage safe" .
:3

[e.salmus]

Re: MacBook Pro 15" 2012 dead

could you try a "copy mage safe" .

What do you mean? I have tried many Magsafe chargers and i also have tried other magsafe boards (with the same part number).

[dellxps15]

Re: MacBook Pro 15" 2012 dead

chip u7000 isl 6258ahrtz or 6259ahrtz pin 1-28 voltage measurement with magsafe plugged in.

[e.salmus]

Re: MacBook Pro 15" 2012 dead

chip u7000 isl 6258ahrtz or 6259ahrtz pin 1-28 voltage measurement with magsafe plugged in.

...and with or without battery?

[dj_ricoh]

Re: MacBook Pro 15" 2012 dead

Do both

[dellxps15]

Re: MacBook Pro 15" 2012 dead

...and with or without battery?

only magsafe

[e.salmus]

Re: MacBook Pro 15" 2012 dead

It has 6259ahrtz

With battery:
1. 15.5V
2. 16.5V
3. 3.95V
4. 2.89V
5. 0.00V
6. 3.31V
7. 0.00V
8. 0.00V
9. 0.05V
10. 0.07V
11. 3.40V
12 3.41V
13. 3.38V
14. 0.03V
15. 0.00V
16. 0.00V
17. 0.38V
18. 5.52V (going lower) stopping at 0.56V
19. 5.48V
20. 5.49V
21. 0.00V
22. 0.00V
23. 3.82V (going lower) stopping at 0.56V
24. 3.51V (going lower) stopping at 0.56V
25. 5.20V
26. 7.96V
27. 7.83V
28. 7.76V

26, 27, 28 discharge at same rate and speed.

Without battery:
Every other voltage is exactly the same but only those differ:
4. 3.38V
17. 0.74V
18, 23, 24 acts same as with battery.
26, 27, 28 discharge at same rate and speed but after first measurement with battery and after removing battery and reinserting magsafe then voltage read was 15.21V

[dellxps15]

Re: MacBook Pro 15" 2012 dead

g3hot 3.42volt measured on pin 12 is ok. so u6990 (ld3470) is ok.

did u already tryed with a smc reset ? power botton keep pressed for 10 second without battery and without psu connected ?

post q7085 , q7080 voltage.and measure r7086
measure also r7010 and r7011 r7012 r7013 value.

u7000 chip already replaced ? did it get hot ?