Macbook pro touchbar 820-00239

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Grazie, no problem.
Actually it tried to change all 4 cd3215 and i am stuck now at 5v and for a second 0.03a on all 4 ports. PPBUS_G3H at 0.2v without short.

I am not sure if i will spend more time on this one.

[mon2]

Re: Macbook pro touchbar 820-00239

Remove the fuse (F7000?) that follows ppbus_g3h and see if ppbus_g3h works ok without the load.

Not in front of the schematics so check the fuse location.

Voltage reading without fuse in circuit?

Do not bypass the fuse, just remove it for testing.

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Thank you mon2.
I took out the fuse and get 20V on charger. Now i am confused.
Does this mean that the cd`s are ok?

Just for my understanding...
I would mention that like on schematic page 66 all connections/values till PIN1 on F7000 are working properly but
with beginning on PAD2 (to System) something is dropping / lets circling my values.

I have no short on PIN2 (about 33MOhm and 0.564 in diode mode)



One more comment :

When i solder out F7000 i get 20V 0a on my meter, when i put back F7000

and take out F8400 (backlight fuse?) i get 20V 0.63a on meter.

[mon2]

Re: Macbook pro touchbar 820-00239

Yes, if you see 20V then your ACE controllers are working. Each must work for you to see 20v from the adapter. This is a good sign.

If the current draw is higher without the backlight fuse then the issue is homing in on the fault on the backlight voltage rail. Leave that fuse off and continue to debug.

Without the backlight fuse and power removed, what is the resistance to ground on the pads for the backlight fuse?

Focus should be in the backlight region for shorts or damaged parts.

Also see here:

https://logi.wiki/index.php/CD3215_Bootup_Sequence

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Hey mon2,

i put back the backlight fuse and ****, it was still taking 0.65.
Putting back into housing it is starting.

It gives me a ?folder.
Recovery is not possible as computer is disabled. I did some work and exchanges on BIOS chip before.

Could you maybe send me a fresh dump regionfree bios?
Somehow i am not able to do this with intel clean me application.

[mon2]

Re: Macbook pro touchbar 820-00239

Cool

The "?" graphics means no bootable media or the contents of your SSD are corrupt. Openly, at this stage I pass on the hardware to other techs to reload the OS.

Perhaps you can wait on others to share their experience on how to load up a fresh OS using a USB media or download off the internet. I know that there are hot keys you can press during power up and the macbook can fetch the OS via the internet to load up a fresh distribution.

Not sure how this works for a disabled macbook but recall some bios hacks from Asia that can change the serial number to fool it. I think that was the solution.

I think you are very close to getting this to work.

[Harryrepair]

Re: Macbook pro touchbar 820-00239

Starting internet recovery always brings me back to "your computer is disabled, try again in 60 minutes."

I need i think a fresh efi dump with ME Region free

[mon2]

Re: Macbook pro touchbar 820-00239

I believe user "Stephen" here in this forum knows about this topic. Perhaps ping him for advice and post your results here.