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820-3330 - MBP 15" 2012 - Dead

Alan.L

Alan.L

Member
not liquid damaged, so gonna be a hard one :/ I don't know the history of this board.

magsafe goes green then orange. so charging is working. but won't power up. I can see fan tries to spin but couldnt.

PCH get hot, I can't keep on my finger on it for long.
so system is trying to get into fully S0 and already partially is in a S0 state,

Dead PCH?


PP3V42_G3H = 3.393v
PPCHGR_DCIN = 16.45v
PPBUS_G3H IS 12.55v
PPVRTC_G3H = 3.3v
PP5V_S3 = 5v
PM_SLP_S3_ = 3.3v
PP3V3_S0_PCH = 3.3v
PP5V_S5 = 5v
PM_SLP_S4_L = 3.3v
MEMVTT_EN = 5v
PP3V3_S0 = 3.3v
PP5V_S0 = 5v
PP1V8_S0_REG = 1.78v
PP1V05_S0 = 0.032v

CPU VCORE = 0
PLT_RESET_L = 0
PM_S0_PGOOD = 0
PVCCSA_PGOOD = 00.05v
ALL_SYS_PWRGD= 0.016v


Q7950
pin1 = 0.018v
pin3 = 0.015v
pin4 = 0.16v
pin5 = 1.071v
pin6 = 3.294v
pin7 = 1.5v
 
J

JohnB8812

New member
So you have a short on PP1v05_S0. Inject voltage to see what's getting hot. Because the PCH is getting hot, start with around 0.5 volts to see if it's the only thing getting warm.
 
Alan.L

Alan.L

Member
JohnB8812 said:
So you have a short on PP1v05_S0. Inject voltage to see what's getting hot. Because the PCH is getting hot, start with around 0.5 volts to see if it's the only thing getting warm.
Click to expand...

just tried, nothing get warm with that small voltage.
 
2informaticos

2informaticos

Administrator
Staff member
10ohms looks like normal value for PCH core.
Check if U7600 gets correct power and enable signal.
ALL_SYS_PWRGD requires its PGOOD to rise up...
 
J

JohnB8812

New member
My known good I have in for backlight has about 100 ohms to ground on 1v05, so idk if it's just a one off, but I could be wrong about short. When you inject voltage does the amperage jump up or stay at zero?
 
Alan.L

Alan.L

Member
it does have short, amperage goes up and I had to rise the voltage to least 2.1v just so I can get 1v readings on the multimeter.
 
Alan.L

Alan.L

Member
when I inject 1v, i get 0.5v reading on the board. inject 2.1v, I get 1v on the board. perfectly fine when you have short like that as long the reading on the multimeter is not 2.1v then you would kill everything on the PP1v05 rail.
 
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D

dukefawks

Administrator
NEVER inject a voltage higher than there is supposed to be. I have no idea what power supply you are using that if you set 1V you get 0.5V because of the short. That means the PSU is current limiting, the wiring is dropping voltage or the PSU is just crap.

This does sound like a dead PCH to start with.
 
Alan.L

Alan.L

Member
yes current limiting. its a switch mode PSU. not very good for the job. I have not killed anything. I does this on most repair as long the multimeter readings for the voltage is not higher than there is supposed to..

I dont have rework station yet, another board to store in the basement.
 
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Alan.L

Alan.L

Member
I want to get a BGA rework station, possibly a Jovy RE-8500, I have like 10 mixers of PC and Mac boards that I require a BGA rework station. if I repair these boards then the BGA rework station will paid for it self once these boards are fixed.

when you want to buy a preball BGA chip from eBay or Aliexpress, how do you search the chip you want?

for example

A PCH for MacBook Pro 15" 2012, it has Intel. E2088369 Platform Controller.

do you search E2088369 or SLJ8C? Are all SLJ8C the same, PC, Macs compatible?

SXGqiQJ.png
 
D

dukefawks

Administrator
SLJ8C should get you the chip you need. ME region will need fixing after replacing but board should at least turn on.

Also don't think you can just replace BGAs when getting a rework station. It requires some practice and patience and "feel" to get things right. Have some crap board to practice on first!
 
D

dukefawks

Administrator
I recommend not to deal with large BGAs. GPUs that are actually real and new are unobtanium so that only leaves the rare PCH replacement. I know you don't wanted to get this answer but this is why these rework stations are on Ebay 2nd hand.

Unless you find a source for real new GPUs you will not use a rework station enough to justify the $1K. I think I replaced 1 PCH so far this year.....
 
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