Macbook Pro A1708 (820-00840-A) Random Death

GadgetsFixLeeds

New member
Hello, I have a pro A1708 that's unresponsive, the fan spins for a few seconds if I disconnect and connect the battery and the Amp pull keeps going up gradually 0.8-3.0, it seems dead but the trackpad vibrates when touch, 13v present on L7030, both 'CD3215COO' as well as the SSD get warm after a good few minutes. Any help would be appreciated, Thanks in advance.
 

GadgetsFixLeeds

New member
forgot to mention it pulls 19.83V and 0.265A with just the board connected to power supply and everything else disconnected and there is a tiny water damage sign like a little drop between R8401-R8402
 
Last edited:

GadgetsFixLeeds

New member
Hi, these are the readings
L7670-- 5.1V
L7690--3.31V
L8410--0V
L7030--13.07V
L7730--1.0V
L7430--0V
L7410--0V
L7420--0V
L7210--0V
L7220--0V
L7370--0V
L8060--1V
L7900--1V
L7960--0.95V
L8030--1.1V
 

2informaticos

Administrator
Staff member
Post resistance to ground at L7370 (ohm scale).
Also check R/C7379 and R7376.
If all OK, try known good BIOS...
 

2informaticos

Administrator
Staff member
L7370 voltage must appear before L7210/20.
But all of them are controlled by same chip, U7100.
These voltages depends by BIOS, U7100 and PCH/CPU.
Very likely bad CPU.

Did you test the board alone on the desk?
No SSD, nor LCD, or other devices; only charger connetced.
 

GadgetsFixLeeds

New member
I have similar issue with another A1708 same board number, only one USB-C port was working, I replaced the port and now it does the same thing, Fan runs once when I reconnect the battery and the CPU and SSD warm up a bit but no display at all
 

2informaticos

Administrator
Staff member
Stop considering the video as the only life sign.
Always check final CPU core voltage on these A1708 boards.
Also USB activity is a must check ALWAYS.

About the second board, if was working before touching USB-C area, CPU core voltage appears now?
I suppose something was affected by the heat applied on that board...
 

2informaticos

Administrator
Staff member
Board can't boot without CPU core voltage.
Check voltage on other big coils; of the second board.

For the future, open separate thread for different boards; even if the same models.
 
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