Macbook Pro 13" 820-3115-B (help for LVDS line components)

[mon2]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

Your wifi connection may be weak. Do you have a USB ethernet dongle ? Consider a wired connection if possible and attempt it again.

https://discussions.apple.com/thread/251479828

[poldo]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

sorgente (1-2-3) = 12,31V

gate (4) = 12,28V

drain (5-6-7-8) = 0,132V

With these values I think the battery should charge, or am I wrong?

[mon2]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

No. Q7055 = AON6403L (see attached datasheet).

This is an Enhancement type P-channel mosfet.

To turn this mosfet ON, the gate has to be a more negative voltage than the voltage you wish to pass.

In your case, the source = gate voltage so the mosfet remains OFF.

When the gate voltage is lower by xx volts (see datasheet) than the source, then the mosfet will turn ON and pass this voltage onto the battery.

Reference:
http://www.learningaboutelectronics....ion%20(VG%20DS).

Remove all power. Meter in resistance mode (2k scale is ok).

Check the resistance for the following:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post your measurements.

[microwave]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

Hi are you using the a1278 J30 Schematic ?.
I also have a a1278 820-3115B board which I purchased with liquid damage but having problems with the trackpad, when I opened the computer up it looks like either a lot of components were removed or maybe never installed on this model, the seller says no work was done to it other than corrosion, the pads look like they were never touched.
Im just wondering if there is another schematic for the a1278 820-3115B.
All I can find is a schematic with J30 in the name, no idea where the J30 comes from.


Thanks

[mon2]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

I have the attached from my paid database.

[microwave]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

Hi thanks for the fast reply, I have no problem paying for the schematic. the problem is I have other a1278 820-3115B schematics but some say J30 in title and other don't until you open the schematic.
Im just wondering is there different models of the a1278 820-3115B, probably unlikely.
Suppose what I really need is good photos of each side of the board.
Its weird I must be missing not far off ten components and the only thing that's not working is the trackpad. Just feels like I have the wrong schematic.

Thanks again, I will open a new post.

[poldo]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

No. Q7055 = AON6403L (see attached datasheet).

This is an Enhancement type P-channel mosfet.

To turn this mosfet ON, the gate has to be a more negative voltage than the voltage you wish to pass.

In your case, the source = gate voltage so the mosfet remains OFF.

When the gate voltage is lower by xx volts (see datasheet) than the source, then the mosfet will turn ON and pass this voltage onto the battery.

Reference:
http://www.learningaboutelectronics....ion%20(VG%20DS).

Remove all power. Meter in resistance mode (2k scale is ok).

Check the resistance for the following:

source (1-2-3) & drain (5-6-7-8)
source (1-2-3) & gate (4)
gate (4) & drain (5-6-7-8)

Post your measurements.

source (1-2-3) & drain (5-6-7-8) = S+ and D- = O.L
source (1-2-3) & gate (4) = S+ and G- = 06,37MΩ
gate (4) & drain (5-6-7-8) = G- and D+ = 07,43MΩ

[mon2]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

The mosfet resistance values look good.

[poldo]

Re: Macbook Pro 13" 820-3115-B (help for LVDS line components)

Your wifi connection may be weak. Do you have a USB ethernet dongle ? Consider a wired connection if possible and attempt it again.

https://discussions.apple.com/thread/251479828

I tried booting with wired connection, it connects but then when the loading apple appears, a few seconds and it turns off.