Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

[Aliseo]

Hello, I'm working on a 2017 15 inch macbook with motherboard 820-00928.

Board is look good, no signes of liquid damaged.

The motherboard takes 20V 1.1A (without battery) but it doesn't start, the trackpad works, caps lock doesn't light up, the fans spin and with an external monitor nothing is shown.

I excluded the usb C area because it takes 20V, I measured the voltages on the big coil, I receive all the voltages, GPU and CPU heat up regularly


PPVCORE_S0_GPU is 0.9V

I tried to flash a new bios but the result is always the same.

Any ideas or advice??

Thanks to whoever will answer.

[mon2]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

Post the exact voltage to ground for PPBUS_G3H and 3V3_G3H.

[Aliseo]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

post the exact voltage to ground for ppbus_g3h and 3v3_g3h.

ppbus_g3h= 12,61v
3v3_g3h= 3,27v

[dclass-pro]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

Have you tried restoring the T2 in DFU mode with another macbook and Apple Configurator app?

[Aliseo]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

Have you tried restoring the T2 in DFU mode with another macbook and Apple Configurator app?

2017 machine haven't T2, i cannot go in DFU

[dclass-pro]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

ok ok have you checked if voltages PP3V3_S5 and PP5V_S5 are generated?

[Aliseo]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

PP3V3_S5 and PP5V_S5 are present

[dclass-pro]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

ok also check if there are:
SPIROM_USE_MLB = 3.3V
PM_PWRBTN_L = 3.3V
PM_BATLOW_L = 3.3V
S5_PWRGD = 3.42V
PM_SLP_SUS_L = 3.3V
SMC_BC_ACOK = 3.42V
PM_SLP_S5_L = 3.3V

[Aliseo]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

ok also check if there are:
SPIROM_USE_MLB = 3.3V
PM_PWRBTN_L = 3.3V
PM_BATLOW_L = 3.3V
S5_PWRGD = 3.42V
PM_SLP_SUS_L = 3.3V
SMC_BC_ACOK = 3.42V
PM_SLP_S5_L = 3.3V

All voltage present

[nrjnapu]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

I have a PC with exactly same symptoms and would like to know if you wer able to resolve it.

[mon2]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

Post the exact voltage to ground for PPBUS_G3H and 3V3_G3H.

Does the unit use 20v to power the board?

What is the current draw? (You can use usb c meter)

[Instafixx]

Re: Macbook Pro 15" A1707 820-00928 no chime,no boot,no image

I have A1706 with the exact same problem - Voltages may vary !

Keen on knowing the result.