MacBook Pro 820-3115 G3H missing

[joesklar]

Hi all,

I'm new to the forums and was pushed in this direction based on recommendation from friends and also YouTubers in the repair community.
Please excuse my ignorance as I'm new to Apple repairs.

I've got a 820-3115 that I purchased as faulty. The laptop obviously had a repair attempt previously and there are signs of widespread liquid damage.

I'm getting no PPBUS_G3H created on the board.
I have PP3V42 across the board.

My input voltage is around 16.6V at DC in. The schematic shows that I should be getting 18.5, is this something to worry about?

After looking the machine over initially I came to the conclusion that I needed U7000 replaced for the OneWire circuit to function. After replacing U7000 I get a green light on the charger, but only for 5 seconds! The green light then disappears for a while and then comes back for 5 seconds.

Again, I'm sorry for my ignorance here, but I'd really appreciate a push in the right direction.

Thanks in advance for your help and I look forward to your responses!

-Joe.

[piernov]

Re: MacBook Pro 820-3115 G3H missing

16.5V is fine with a 60W Magsafe. Don't blindly trust the voltage indication on the schematics, they will almost always mislead you.
Measure exact resistance to ground on PPBUS_G3H.

[joesklar]

Re: MacBook Pro 820-3115 G3H missing

16.5V is fine with a 60W Magsafe. Don't blindly trust the voltage indication on the schematics, they will almost always mislead you.
Measure exact resistance to ground on PPBUS_G3H.

Thanks very much for the response.

My resistance to ground on PPBUS_G3H is 0.840kΩ.

[joesklar]

Re: MacBook Pro 820-3115 G3H missing

Just updating after some probing.

Pins 27 and 28 of U7000 both have no resistance.
C7030 and C7031 are also showing as short in diode mode.
Q7085 does not open even though there is a lesser voltage on the gate.

I hope this helps anyone who can make more sense of schematics than I can

Thanks very much.

[leovalpo]

Re: MacBook Pro 820-3115 G3H missing

https://www.youtube.com/watch?v=dIuEYPOHlEU&t=1207s

[ktmmotocross]

Re: MacBook Pro 820-3115 G3H missing

Just updating after some probing.

Pins 27 and 28 of U7000 both have no resistance.
C7030 and C7031 are also showing as short in diode mode.
Q7085 does not open even though there is a lesser voltage on the gate.

I hope this helps anyone who can make more sense of schematics than I can

Thanks very much.

u did not add schematic or link to it so we cannot help

[joesklar]

Re: MacBook Pro 820-3115 G3H missing

u did not add schematic or link to it so we cannot help

Hi there,

Sorry for the delayed response, I've been busy with work.

I've attached both the schematic and boardview

[MtapeK]

Re: MacBook Pro 820-3115 G3H missing

Hi there,

Sorry for the delayed response, I've been busy with work.

I've attached both the schematic and boardview

did you eventually solve your macbook's problem?

[MtapeK]

Re: MacBook Pro 820-3115 G3H missing

i have the same model that does the same thing... but mine switch on with battery and not MagSafe... i would recoment you to to the same maybe you'll be shocked to see it actually power on then u might not need to replace U7000 after all