Macbook Air A2337 not turning on - ISL or CD issue?

[tomtom67]

Have an A2337 here, which suffered some serious coffee damage. After cleaning C5220 fell from the board, so I replaced it and after lifting the ISL I found pad C5 was also partially corroded, first reballed the original ISL (no power), and then replaced it from a donor.
I now get 5V / ~10mA stable on the charger, and found the CHGR_GATE_Q2 (GATE_Q2 on the ISL) doesn't get activated (Q1 does).

Is this an ISL or a communication issue (perhaps with the CD3217s)?

[tomtom67]

After thinking a bit longer, i think both GATE_Q1 and GATE_Q2 should oscillate. Will find another donor tomorrow to transplant the third ISL on that board. Didn't find any shorts, and diode readings around the isl are ok, too.

[mon2]

Check the LDO rails on each CD3217.

CD3215 Bootup Sequence - LogiWiki