MBP 2017 A1708 no start

[Eon]

Bonjour,
j'ai un problème avec un macbook pro qui ne démarre pas et pas d'écran, pas de gong, ventilateur tourne puis s'éteint.
Pas d'oxydation apparente.
Mesure faites :
quand usb charge branché 19v et 400mA

PUCE : 7650
PPBUS_g3H : 13,08v
P3v3_S5 : 3,3V
PPBUS_G3H_P3V3S5 : 13,08v
P5VXX_EN : 3,42v
P5VS4_EN : 3,3v
P3V3S5_EN: 3,42v
P3V3S5_DRVL_R : 1,06v
P5VS4_DRVH_R : 5,25v


Merci de m'aider

Good morning,

I have a problem with a macbook pro which does not start and no screen, no gong, fan spins then turns off.

No apparent oxidation.

Measurement done:

when USB charging plugged in 19v and 400mA

PPBUS_g3H: 13.08v

CHiP : 7650
P3v3_S5: 3.3V
PP5V_S5: 5v
PPBUS_G3H_P3V3S5: 13,08v
P5VXX_EN: 3,42v
P5VS4_EN: 3,3v
P3V3S5_EN: 3,42v
P3V3S5_DRVL_R: 1,06v
P5VS4_DRVH_R: 5,25v





thank you for helping me

 

[2informaticos]

First of all, welcome to the forum!

Which other big coils get voltage?
Apart of 3V3_S5 and 5V_S4.

 

[Eon]

Merci !
I don't know which coil to measure

 

[Eon]

why do I have P3V3S5_DRVL_R: 1.06v and not 3.3v?

 

[2informaticos]

L7900/60, L8030/60, L7730, L7370, L7210/20.

 

[Eon]

L7900: 1V L8030: 1,1v L7730: 1v L7370: 1v L7210: 0,9v
L7930: L8060: 1v L7220: 0,9v

 

[2informaticos]

L7210/20 should drop to 0.65V when board really boots.

What the client said about how the problem appeared?

You can try known good BIOS.

 

[Eon]

THANKS
How do I flash bios if I have no screen (no display)? Do you have a solution ?

 

[2informaticos]

I suppose that you don't have Medusa programmer.
So you need to remove the BIOS chip and use USB programmer; like CH341, or similar.