SOLVED - 820-01521 air retina stuck at 5V 0A

[jadao]

This one looks clean, I have 5V 0A.

PP1V8_SLPS2R is missing and diode mode is 0.330 seems a little bit off from 0,390 so I am not sure... resistance to ground is high on both boards arounf 500kOhms.
PPBUS_G3H is 0,42V with no short, diode mode is 0,455 same compared with other board.
PP3V3_G3H is missing but I think it's normal with PPBUS_G3H missing/low
PPDCIN is 5V and I get 5V on both sides of R7075 (U7000's VDDA and VDDP)

I think PP1V8_SLP2R is needed for U7000. Any guidance would be appreciated.
Thanks!

 

[2informaticos]

"I think PP1V8_SLP2R is needed for U7000"
Not really; only needed to adjust final value.

On T2 boards, PPBUS_G3H is the mother of all voltages.
ISL9240 can generate PPBUS_G3H with only 5V at R7020.

Post other U7000 voltages; AUX_DET, AUX_OK.
Also check diode mode to ground at C6960/70 and C7080.

 

[jadao]

Thanks for the info, very valuable!

I do have 5V at R7020.
AUX_DET is 1.3V witch seems ok according to the 5V going actually through the voltage divider.
AUX_OK seems to be NC "NC_CHGR_AUX_OK"
CHGR_RST_IN is 0V
At C6960/70 and C7080: I have 0,455 in diode mode.

 

[2informaticos]

Looks like bad ISL9240, change it.

 

[jadao]

Hi 2informaticos, just to let you know that replacing ISL9240 solved the problem.
Had to wait until I found an ISL9240 from a 820-01700.
Thanks as always!

 

[2informaticos]

You're welcome!

Nowadays, a simple repair went very dificil, just because Apple doesn't allow the manufacturers to sell the chips to anybody else.