Macbook Pro - Water Damage - 820-4924 A1502

HI , I have a Macbook Pro board 820-4924 with water damage, no start
water damage around the U500 chip, fan no spin, green light and then orange light
posted voltages with out battery
PP18V5_DCIN_FUSE=16.52v
PP3V3_S5=3.34v
PM_BATLOW_L=3.34v
SMC_ADAPTER_EN=3.38v
SMC_PM_G2_EN=3.41v
PPBUS_G3H=12.57
IC U2800 its geting hot
 

2informaticos

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U2800 is thunderbolt controller.
If gets hot, some S0 voltages should be present.
So your board turns on, but not booting; make difference between these things.

Fan will not spin until CPU gets very hot; don't use the fan as power on sign for this board!

Post voltage on big coils of the board.
Also check for USB activity.
 

2informaticos

Administrator
Staff member
"USB=5.12v"
What this means???
You have a fix with USB power.
I said you to read "How To colleciton" thread, about how to properly check USB activity.

The board stays on and has even CPU core voltage.
Need to confirm USB activity, eventually external video.
Do you get PLT_RESET_L at least?
 

2informaticos

Administrator
Staff member
Then no USB activity for sure.
I hope you understood how to check it, for the future.

Inspect U1950 for corrosion.
Do you get 3V at pin 3?
 
I notice that when I connect the charger the cpu gets hot and when 1 minute pass start to getting cold and then only voltage on L7130=12.56 and the rest of the big coils =0v
 
Now PLT_RESET_L =3.34v, put everything together and when I started i can hear the chime, but no video, Boot into an OS using HDMI out with internal display but no video, L8300 =5.17v for 5 seconds and then 0v, PP3V3_S0_EDP_SW =3.34v for 5 seconds and then 0v, SMC_LID=3.38 stable
 

2informaticos

Administrator
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Looks like CPU (iGPU) problem.

With internal LCD connected, check if LCD_HPD_CONN and DP_INT_HPD go high; at same time when you get 3V at pins 28-30 of J8300.
 

2informaticos

Administrator
Staff member
Fan only starts to spin when CPU gets really hot; is the normal behaviour for this board.

If DP_INT_HPD goes high, PCH should enable eDP output.
If signal drops after few seconds, denotes iGPU problem; this explains missing external video too.
 
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