820-01700 no power


New member
Hi Everyone,

I have this board 820-01700; no history, no liquid.

it’s not recognize in DFU/ Apple Configurator.

Reading on meter is 5V, ~0.455amp; reading taking with board outside enclosure.

PPBus is fluctuating ~ 8v.

Slp and awake power is cycling from U7800.

I can not find any short anywhere.

I have replaced U7000, but same result, still around 8v on ppbus.


New member
This is solved.
Found PP3V3_G3H_RTC fluctuating around 1.6V-1.7V at L6960 and L6961. After a closer look at U6960, found corrosion on the outside of the chip. Replace U6960 and everything is good.