[SOLVED]820-00165- Won't Start off the battery.... Stumped

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TCRScircuit

Super Moderator
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Customer came in with a A1466 with a 820-00165. She said it froze and shut off and wouldnt come back on. Customer brought it to apple, diagnosed as bad battery. They replaced the battery and the problem remains. They sent it to me... No signs of liquid damage, Works fine off the charger... If i plug the battery in PPBUS_G3H is at 8.49 v. PPV3.42 is present. There is no fan spin. However, if i Plug the charger in it starts. If i remove the charger, it runs fine as long as you start it with the charger.

Here is where things get interesting.... I was measuring voltage at the SMC When I accidentally touched the meter lead between R5170 and R5172... The fan started to spin and the board started... So that must mean the SMC is not on when the battery is plugged in. It passes ASD on battery and when plugged in. The customer is really nice and would like to get this board fixed. Thank you to any help you can provide me. I ordered a TPS51980A (U7501) Becuase that is my guess to what the probelm is.
 

TCRScircuit

Super Moderator
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It won't Start even if all of that is unplugged. I have the board on my bench and when I plug the battery in the board does nothing... No fan spin unless i short the pins... If i plug the charger in it starts fine,
 

dukefawks

Administrator
That is normal. When AC is connected after all power was removed the board auto powers on. When on battery or after a shutdown you need to press the power button.
 

TCRScircuit

Super Moderator
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After more diagnosing, the board operates normally with they keyboard flex cable unplugged, however, when the keyboard is plugged in, the board won't even start if I jumper R5115. So what would cause it not to start with the keyboard plugged in?
 

dukefawks

Administrator
A bad keyboard....

You can test with any apple unibody keyboard to see if power button works, they all have the same pinout.
 

TCRScircuit

Super Moderator
Staff member
I cleaned the cable, It starts now with it plugged it, but immediately you can smell burning board from the trackpad area.
 

dukefawks

Administrator
I assumed you check the trackpad to board cable. The cable is fucked if it is corroded. If it has been burning the connector is also probably fucked now. Clean everything up and try with a NEW cable.
 

TCRScircuit

Super Moderator
Staff member
Thanks for your help Duke. The new cable still burned and after looking at the trackpad logic board under the microscope it is fucked up bad. Sold customer new keyboard and trackpad.
 
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