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A2141 820-01700-A DONT TURN ON

K

kashitozu

Member
hello,

1- I have a MacBook A2141 and its dont turn on

i have first 5v and after 20v that its normal but i have 0.057 A

not short circuit on the nand but 0v everywhere on the nand

L7660 (PPV3_g3h_t) OK (i have 3v)

L7600 (pp5v_g3s) 0v not short circuit and i have 396 ohm

i have change U7650 but its the same

i have change U7800 but its the same

and all of voltage on the T2 is good (P1V8.. +P0V9.. + P1V1.. is good)

On R7691 i have 0v is for that i have change U7800

On R7900 its ok i have 3v3 in and out

what can i do please

2- I want to know if 5v is necessary for starting or not please

3- when the computer enters dfu mode I have to have the voltage on the nand, do we agree?

4- and do you have the cycle of boot tension

thanks for the reponse
 
2informaticos

2informaticos

Administrator
Staff member
First of all, welcome to the forum!

1- any history available?
2- 5V will appear later, in the startup process.
3- not agree; many times we need to complete DFU restore, in order to recover SSD's voltages.
4- not sure what you mean there.

Be aware, this machine requires 96/140W charger to power on; if battery is depleted.
 
K

kashitozu

Member
2informaticos said:
First of all, welcome to the forum!

1- any history available?
2- 5V will appear later, in the startup process.
3- not agree; many times we need to complete DFU restore, in order to recover SSD's voltages.
4- not sure what you mean there.

Be aware, this machine requires 96/140W charger to power on; if battery is deplete
Click to expand...
Thanks !

1-its the history

2- thanks

3- I have enter the MacBook in DFU mode but i dont have tension and apple configurator dont detect the macbook but I have the notification that I have connected a device in a thunderbolt port

4- je veux juste connaître le cycle de démarrage du macbook avec tension

What do you advise me to do now??
 
2informaticos

2informaticos

Administrator
Staff member
You still didn't say how the problem appeared.

Do not use thunderbolt cable for DFU; get charger cable, USB 2.0 is required.
Are you using original 96W charger?

I'm not sure if you asked for power on sequence, or something else on point 4.

BTW, write directly into reply box, instead of clicking Reply button.
I don't see any reason to quote an entire post, visible few centimeters above.
Please, maintain forum asthetic.
 
K

kashitozu

Member
the customer brought it to me like this, there was no liquid inside and a short circuit

thanks and i use a power supply

yes i ask for power on sequence

sorry for that
 
K

kashitozu

Member
I cant is say « too large » but the message is :

Gave up waiting for device to transition from DFU
state to DFU state.

[com.apple.MobileDevice.MobileRestore - OxFCA
(4042)]
 
K

kashitozu

Member
Thank you but you think it's rather the SSD or the T2

Which hard drive fails most regularly?

when it enters dfu mode and after I restore is it obligatory to have the voltage on the NAND?
 
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