820-00239-A No Power

twitchedonjay

New member
Good Day,

I am new to macbook PCB Repair but I usually fix iPhone and iPad PCB so I have some knowledge and skill . Please bare with me.


I have a Macbook 820-00239-A board which got water damaged now we have no power.

With battery disconnected and charger plugged in

PP3v3_G3H - Present (3.4v)
PPBUS G3H - Present (13.xxv)
PM_SLP_S5_L - Missing (0v)
PP3v3_SUS - Missing (0v)

Can anyone assist me with this repair?
 

twitchedonjay

New member
Okay so after some checking I see that allot of the lines missing have switches powered by pp3v3_s5 in common so I am guessing that is missing (will check when I get to the office. Providing that is missing I will have to check the lines at U3400. Can anyone correct me if I am wrong?
 

2informaticos

Administrator
Staff member
3V3_SUS must appear before 3V3_S5.
Where was the spill?
Check PM_BATLOW_L, PCH_INTRUDER_L, PM_DSW_PWRGD, PM_SLP_SUS_L, RTC_RESET_L, PCH_SRTCRST_L.
Do you get 32KHz from U1900 for PCH?
Also check presence of PP3V0_G3H (RTC voltage).
 

twitchedonjay

New member
Thanks for your reply. I will check the lines you mentioned when i get to the shop but I don’t have an oscilloscope so i won’t be able to check the signal . Maybe i’m reading something wrong because I swore I saw in the schematic that 3v3_s5 enables 3v3_sus.
 

twitchedonjay

New member
PM_BATLOW_L = 3.3v
PCH_INTRUDER_L = 2.8v
PM_DSW_PWRGD= 3.4v
PM_SLP_SUS_L= missing
RTC_RESET_L= 3v (found a shorted cap while measuring , was 110mv before)
PCH_SRTCRST_L= 3v
PP3V0_G3H= 3v

as i type PM_SLP_SUS is back now that i removed the bad cap
3V3_S5 is back
3V3_SUS is back

I think I may have just repaired this overpriced macbook. will update you
 

twitchedonjay

New member
Okay so every thing was great! Powered on and I found the reason for the folder. Macbookbook was booting. Put the board back in, screw it up and no power again. Now I have OL on PP3v3_G3H. PLEASE help
 

2informaticos

Administrator
Staff member
You must pay more atention with the screws.
Possibly some of them damaged the board; inspect any area corresponding to the screws.
Check again the board alone on the desk; maybe some peripheral device makes problems...
 

twitchedonjay

New member
Okay I think I have narrowed the problem down. Okay so I pulled down the system to inspect. No long screw damage. Al ways are there so I decide to to put it back up and it works. Used it for about an hour turning it off and on to make sure everything is good. Turn it off and install the 3 antenna wires and no power again. When I check the 50_0_ANT, 50_1_ANT and 50_2_ANT all have a beep for short to ground. Is this a norm because of low resistance? The laptop is back at no power state.
 

twitchedonjay

New member
Well firstly the beep on the ANT lines is normal. I tested on another board.

I pulled the unit back down then assembled it again and it worked.

The bad cap on RTC_RESET_L fixed the problem
 
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