A2442 pulls 20v seems to boot and then crashes

[Vliegenier04]

Hi! I've got an A2442 board that had severe explosion damage to Q5240 and surrounding area. I managed to patch it up and every test point seems to work. Now the Mac turns on, briefly, for just approximately 1-2 seconds and then turns off. It never manages to boot fully or stay on for longer than 3 seconds.

PPBUS_AON is good (12.32v)

Who has an idea regarding this matter?

 

[2informaticos]

Is the battery charging?
Did you test with charged battery?
Did you try to enter into recovery?

 

[Vliegenier04]

Upon connection battery it pulls ~ 89W, so I figured yes. But the Mac doesn’t stay on, even with battery.
Recovery works - for 1-2 seconds until the Mac goes looping again. It never finishes loading.

DFU mode using DFU BLASTER Pro doesn’t work either.

 

[2informaticos]

Check resistance (ohm scale) over C5220/60.
Also check CHGR_BMON level, when board is on.

 

[Vliegenier04]

C5220/60 = ~20k hard to measure. I think I'm doing this right but not sure.
CHGR_BMON with or without battery attached?

 

[2informaticos]

CHGR_BMON is battery current related; so, yes, test with battery connected.

"C5220/60 = ~20k"
Did you check between the pins of each capacitor (not to ground, nor between caps)?