Hi,
I've got an old, but still useful, 15" Macbook Pro, Mid 2010. Recently it stopped powering on. Still get a green light on the charger cable.
When I try to power it up I get a clicking noise, which I've found is coming from within the battery. With that disconnected, and trying to start in bypass mode, I get another clicking noise - this time it's an inductor on the board.
I'm trying to self-diagnose the problem using the board view and schematics. It's all new to me so it's an educational thing to do in lockdown at least. Bear in mind I was never any good at electronics at school...
All the main power rails seem to be correct and present either on battery or mains power, but I've noticed an anomaly here, where the highlighted text is:
There's 3.42v going in to resistor R4999 as expected (from the power rail PP3V42_G3H), but there is also 3.42v the other side of the resistor, rather than the 3.3v that should be there. The resistor is still working, I've measured it, so that means the 3.42v must be present coming up the other side of the resistor, right? Capacitor C4920 seems OK, no short in it.
U4900 is the SMC chip, so I'm suspecting the chip has gone and is shorting the 3.42v line somewhere.
I'm still doing other tests, so I'll post any more info I find, but if anyone out there knows a little about this stuff and can point me in the right direction, or just say, "Yeah, the chip is screwed, that's it," then I'd be grateful.
Cheers.
I've got an old, but still useful, 15" Macbook Pro, Mid 2010. Recently it stopped powering on. Still get a green light on the charger cable.
When I try to power it up I get a clicking noise, which I've found is coming from within the battery. With that disconnected, and trying to start in bypass mode, I get another clicking noise - this time it's an inductor on the board.
I'm trying to self-diagnose the problem using the board view and schematics. It's all new to me so it's an educational thing to do in lockdown at least. Bear in mind I was never any good at electronics at school...
All the main power rails seem to be correct and present either on battery or mains power, but I've noticed an anomaly here, where the highlighted text is:
There's 3.42v going in to resistor R4999 as expected (from the power rail PP3V42_G3H), but there is also 3.42v the other side of the resistor, rather than the 3.3v that should be there. The resistor is still working, I've measured it, so that means the 3.42v must be present coming up the other side of the resistor, right? Capacitor C4920 seems OK, no short in it.
U4900 is the SMC chip, so I'm suspecting the chip has gone and is shorting the 3.42v line somewhere.
I'm still doing other tests, so I'll post any more info I find, but if anyone out there knows a little about this stuff and can point me in the right direction, or just say, "Yeah, the chip is screwed, that's it," then I'd be grateful.
Cheers.
