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MB pro 820-3332-a , black screen , fan spins crazy .

Petro

Petro

Member
Hi all , i have a problem with me macbook pro retina 820-3332-a , it turns on and give sound only by holding the power button and then plug the charger in , black screen , fans spins high even low temp . charger looks good from green to orange .

if it's possible to give me the steps to diagnose would help me really

thanks,
 
Petro

Petro

Member
Yes green then orange , but when i plug the charger in the mac don;t start up it self i need to hold the power button for 6 7 sec and it starts.
 
2informaticos

2informaticos

Administrator
Staff member
Looks like it only starts in SMC bypass.
Post exact resistance between pins 17/18 and 27/28 of U7000.

Any history available, liquid signs?
 
Petro

Petro

Member
No Sir , no liquid , 4 years ago i it just turn the screen black and leaves it in the box ,cuz i thought it is the GPU , so i tried heating a little wih a hair dryer and it turns on for a bit and than again now i want really to know whats te problem just im into learning microsoldering big thanks to louis who insipred me for that.

So , when i press the power button and put the charger in by holding the pw button it starts to run and make the welcome sound but also the fans starts to run really fast i dont see any damge on the board .

So pin 17/18 resistance is 03.90 pin 27/28 is 21.17 .

what dose this mean ?
 
2informaticos

2informaticos

Administrator
Staff member
Please reply with new post, not a comment.

Fan runs at max when start in SMC bypass, is normal.

Do you have original 85W charger?

Check if PM_BATLOW_L is high level.
ALso check if AVREF_SMC voltage is present.
Post voltages for SMC_DCIN_VSENSE, SMC_PBUS_VSENSE, SMC_DCIN_ISENSE, SMC_CHGR_BMON_ISENSE.
 
Petro

Petro

Member
im not sure !! but with that it turnet ON by smc bypass ? not u f**k up the u700 just wantet to resolder now i get a short get really hot !!
 
2informaticos

2informaticos

Administrator
Staff member
Connect to an working machine and check power in system report.
15" will NOT start with 60W charger; unless the battery is connected and has some charge on it.
 
Petro

Petro

Member
i toke out the chip and the charger light is fine , when i put it on it get shortet ? is smth wrong with the u700 chip ? also check email .
 
2informaticos

2informaticos

Administrator
Staff member
You will get light even with 45W cable.
But machine doesn't start without 85W charger, if no battery (charged) present...
 
Petro

Petro

Member
I?m using a power supply ? Is that a problem ? Idk what watt is the head of the charger should i get a 85w head ? And before i took the U7000 the mac startup fine in bypass mode just the fans spins fast and the battery was not recognized ? What are the diagnosing steps now ?
 

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2informaticos

2informaticos

Administrator
Staff member
That is normal behaviour for SMC bypass.
You should check AVREF_SMC voltage first.
If OK, need to check SMC sensors level.
And yes, head cable must be 85W...
 
Petro

Petro

Member
I accidentally touched C7016 with C7002 with the prob by measuring the voltage ! now i dont have pp3v42 ? can't find the burning cap ? replaced u6900 , u6901 still now power ?
 
Petro

Petro

Member
I took the u7000 off ? last time it was not connected and still got the 3v42 volt ? should i check smth else ?
 
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