macbook pro A1706

[hani002]

the fans spin and all the general voltage present
the usb amp meter start from 20v , 0.23A then the amp goes to 0.01 then return back to 0.23
there is no picture and the capslock not light.

[zpi]

Re: macbook pro A1706

Hello,

Voltages present on:
L7430
L7410
L7420

?

[hani002]

Re: macbook pro A1706

no not present
0 volt

[zpi]

Re: macbook pro A1706

Previous repairs ?
Liquid damaged areas ?

[hani002]

Re: macbook pro A1706

no previous repairs
there is small liquid over u7430

[zpi]

Re: macbook pro A1706

L7430 ohms to ground ? With power disconnected offcourse.

[hani002]

Re: macbook pro A1706

3 ohm

[zpi]

Re: macbook pro A1706

Remove or pull up one side of all three. Better pull up one side woth soldering iron (cpu is to close to use hot air now)

L7430
L7410
L7420

Then meassure ohms to ground of

L7410 pin1 and pin2
L7420 pin1 and pin2
L7430 pin1 and pin2

[hani002]

Re: macbook pro A1706

morning i will do it
thanks for help
any more sugestion to try

[zpi]

Re: macbook pro A1706

If 3ohms will still be on pins 2, then cpu is dead.
If 3ohms will be on one of three pin 1's then you need to find short, probably u7430 because of liquid damage. Thing is that liquid on u7430 may triggered to open mosfet and send source voltage directly to cpu and killed it. But it may also be opened to ground and only be shorted. So need to find out if cpu is not already dead first.

[piernov]

Re: macbook pro A1706

What's the issue with 3 ohms to ground on iGPU VCore?
If there is liquid damage first thing to do is a close visual inspection to identify affected area. If no hints, always go through the list of power rails and measure voltage.

[zpi]

Re: macbook pro A1706

What's the issue with 3 ohms to ground on iGPU VCore?
If there is liquid damage first thing to do is a close visual inspection to identify affected area. If no hints, always go through the list of power rails and measure voltage.

As i remember normal is 10-15ohm? Or maybe i am thinking about other board