I’m really new to the switch, logic board is taking 5V but not charging at all, there’s no shorted caps around M92T36, P13USB, BQ24193. The usb-c port looks good. Anything to look for? On M92 chip I’ve got 0V pin 6 and 4V pin 5 when DC IN connected (no battery). Any idea what else can cause this?
Sometimes even though theres no short on m92 doesnt mean its good try removing it and replace with another
Ive replaced a lot of them and and noticed that no shorts on it doesnt mean its good
It’s unlikely to be an M92 issue with a dead short on the boot CPU rail
Most likely the SoC is toast, you can pull the inductors and see which side the short remains on to get a better idea but I expect it will remain CPU side.
I have that feeling too… APU does not seem so visually Bad, but maybe it is.
Can you please show me where they are and how to make this test? Thank you.
even if APU is toasted, switch should not be able to recharge battery?
The two you highlighted in black bud
Done, short remains on the left part of logic board for both inductors. Does it mean the ends of this jurney? It still not charge battery. There is any hope that there is some solder ball joints under the APU causing the shorts caused by attempted reflow?
It’s pointing towards the SoC unfortunately
I notice from your other image the Max IC has also been reflown, you might wanna pull that chip just to rule it out
If it’s been reflown then it’s possible, it’s also possible the heat has killed it too
Did you checked the fuse if it’s okay? If it’s damaged, the board will not draw any Power.
Doesn’t matter whether the fuse is open or not, it has a dead short on the boot CPU rail
Just to avoid confusion (for myself), you mean pull of Chips Power Control IC MAX77620AEWJ+T
( PMIC ) or the IC regulator MAX77621?
This one, though tbh I don’t think it will change anything, if the SoC has been reflown and looking at your other topic (unless it’s a trick of the light) the SoC resin round the die has gone brown, this typically causes death of the SoC and drags the CPU rails down and a few others (which it has in your case based on some of your other measurments in the other topic)
I’d just reserve this board as a donor at this point sorry to say
As you said, removed but short persists. I’ll keep as donor/practice board Best thing of repairing something? Is repairing of course… But that’s not my day. I hope that next time I will and get that feeling of happiness you got when it’s working
the next ones a win