Hi all
This laptop was my wife's, a little water dripped onto/into it while it was stowed in her backpack. Unfortunately she couldn't wait and tried turning it on right after she realized what had happened - "It didn't turn on but got hot."
Since I'm naturally curious and I hate to throw hardware away I figured I'd have a go at and see if I can repair it.
I've been searching for info on this particular machine but there's so much stuff I'm having a hard time putting it all together.
The power sequence for example is still unclear to me.
Here's where I'm at:
- Took the laptop apart, I have the board out, nothing connected to it.
- Cleaned all traces of corrosion, mostly around U3200, UB300 and UB400 (all CD3215)
- U8400 is toast with visible heat damage on the chip right at pin 5 (I've removed the chip)
- Other than U8400, there are no visibly/obviously burnt components
- Using the original Apple Power Supply I get 5.17V PPDCIN_G3H, I get this behaviour for all 4 USB-C ports
- When I supply power (5V) from a bench supply there's approx. 20mA current draw
- PPBUS_G3H: 0.0V
- It looks like PPBUS_G3H has is shorted (resistance to GND is below 1 Ohm), however, even with injecting 1V@1A (I started at only 50mA) on PPBUS_G3H nothing gets even remotely warm (using a thermal camera)
- If I have no PPBUS_G3H, is it likely that U7000 (ISL9240) is dead too?
- In trying to locate the short on PPBUS_G3H, how much current is safe to insert at what voltage?
- Am I going at this the right way?
Any help and insight is much appreciated
Thanks for reading
This laptop was my wife's, a little water dripped onto/into it while it was stowed in her backpack. Unfortunately she couldn't wait and tried turning it on right after she realized what had happened - "It didn't turn on but got hot."
Since I'm naturally curious and I hate to throw hardware away I figured I'd have a go at and see if I can repair it.
I've been searching for info on this particular machine but there's so much stuff I'm having a hard time putting it all together.
The power sequence for example is still unclear to me.
Here's where I'm at:
- Took the laptop apart, I have the board out, nothing connected to it.
- Cleaned all traces of corrosion, mostly around U3200, UB300 and UB400 (all CD3215)
- U8400 is toast with visible heat damage on the chip right at pin 5 (I've removed the chip)
- Other than U8400, there are no visibly/obviously burnt components
- Using the original Apple Power Supply I get 5.17V PPDCIN_G3H, I get this behaviour for all 4 USB-C ports
- When I supply power (5V) from a bench supply there's approx. 20mA current draw
- PPBUS_G3H: 0.0V
- It looks like PPBUS_G3H has is shorted (resistance to GND is below 1 Ohm), however, even with injecting 1V@1A (I started at only 50mA) on PPBUS_G3H nothing gets even remotely warm (using a thermal camera)
- If I have no PPBUS_G3H, is it likely that U7000 (ISL9240) is dead too?
- In trying to locate the short on PPBUS_G3H, how much current is safe to insert at what voltage?
- Am I going at this the right way?
Any help and insight is much appreciated
Thanks for reading
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