820-2914-B Macbook EFI reset to wipe password, now no power??

[drnict61]

Greetings! I got a 17" Macbook Pro that I tried resetting the EFI password on. The computer still turned on and charged.

I was able to read and verify three dumps from the EFI chip, then I modified it removing the two $SVS sections and flashed it to the chip successfully.

Now the laptop won't show any lights on the charger, or the battery status lights, and nothing happens when I try to turn it on.

I did not remove the EFI chip from the board when doing my work. I followed this guide: Mac EFI Password Removal (Github)

What did I do : ( What do I do now? I'm willing to dig in with a multimeter, fine tip soldering iron, and micro heat gun

I've attached the original and my modified bins.

Thank you!

Machine Info: A1297 Macbook Pro 2011 i7, board 820-2914-B, EFI chip Micron 25Q064A

[zpi]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

i delete only first $svs block, also perform pram reset on first start after reflashing bios.

[drnict61]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Thanks for the reply; Unfortunately I just tried only replacing the first instance of $SVS from the bin, verifying every read and flash along the way with md5sum. Still, no signs of life on the laptop or charger

[qayyum786]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Thanks for the reply; Unfortunately I just tried only replacing the first instance of $SVS from the bin, verifying every read and flash along the way with md5sum. Still, no signs of life on the laptop or charger

1st) in case you use jumper method than check voltage on pin no 8 if it is present (if jumper method went wrong can be cause to dead)

2nd) if you have make backup of original dump before flashing than you may try the original backup and check if laptop back to the life

[piernov]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Magsafe LED is completely unrelated with SPI ROM.

[zpi]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Measure pp3v42_g3h when magsafe connected, also check sys_onewire

[drnict61]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

pp3v42_g3h measured at c5750 and c5755 and c6908 0.0v

sys_onewire measured at r6929 0.0v

doesnt seem to change with any combination of magsafe + battery

[zpi]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

So your problem pp3v42_g3h, it is first rail to power up after dc in rails. Measure U6990 pin7, pin4 only with MagSafe connected. Also measure resistance to ground on L6995 without charger.

[drnict61]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

U6990 measured 16.8v
L6995 w/o charger multimeter beeped at me on both sides of the inductor

Inductor bad?

Tysm

[zpi]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Inductor never goes bad . You have short on your pp3v42_g3h rail.
Do you have lab power supply ? If no, you have to lift one side of L6995 and measure resistance to ground in ohms on both sides, only one will show low ohms, let me know which one.

[drnict61]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Lifting it! Pin 2 beeps, nothing on pin 1 : )

[zpi]

Re: 820-2914-B Macbook EFI reset to wipe password, now no power??

Ok, so something is shorting on output of pp3v42_g3h, you have to inject 1-2volts in L6995 pin 2 (probably will be some capacitor) and try to find hotspot. You also can open boardview (i assume you have it) and inspect all places where pp3v42_g3h goes.