820-3435-b 11.6 macbook air

pcfriends

New member
A1465 11.6 MacBook air

PPBUS_G3H : 8.4V
PPBUS_S5_HS_COMPUTING_ISNS: 8.4V
PPBUS_S5_HS_OTHER_ISNS :8.4V
PP3V42_G3H: 3.4V
PPVRTC_G3H:3.1V
PP5V_S5 : 5V
PP3V3_S5: 3.3v


PP5V_S0: when I diode test it shows .003 and .005 and beep to ground booth sides

U7320 was getting really really hot burning lips man , I remove it to check if that remove short on the 5V_S0 but nop.

What should me my next step? I was thinking on injecting voltage to the 5V_S0 line and find out where is getting hot?

any other rails I should check?
 

larossmann

Administrator
Staff member
put 1v on PP5V_S0. What gets hot?

Nothing? Raise voltage 0.5v and keep it going until you figure it out.

Is there no short on PPBUS_S5_HS_COMPUTING_ISNS? If U7320 dies, it can screw up Q7320 and Q7321. U7320 tells Q7320 and Q7321 when to turn on. If U7320 is destroyed, it might just tell Q7320 and Q7321 to always stay on, which burns them so they are always stuck on..which means they are always feeding U7320 8v.

AND THE CYCLE CONTINUES! :(

I would inject 1v and go from there. Pouring a layer of alcohol over the board makes this easier, wherever it fizzes, look there.
 

pcfriends

New member
put 1v on PP5V_S0. What gets hot? = C7710 I remove it and short is gone , im going to replace the U7320 for another one check rails and update what happened after that.
 

pcfriends

New member
well no voltage on L7320 and L7310 , so Louis I should try replacing Q7310 AND Q7321 and U7320 all at the same time right?
 
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