820-02016 No Power - Cycling

bls951

New member
Hello,

I have an 820-02016 that is stuck at 5v and cycling. My amp meter reads 5v with 0.1 amp before the amps drop to zero and my meter turns off completely before turning back on, repeating what I mentioned. The only history I have of the machine is that it stopped working after the trackpad was hit. The machine is otherwise in clean condition, there is zero liquid damage. The machine is also not able to enter dfu mode.

PP3V8_AON_VDDMAIN - 3.8v
PPBUS_AON -12.26v
PPVDD_SOC_S1 - 0.663v
PP1V8_S2 - 1.8v
PP2V5_AWAKE_NAND - 2.5v
PP1V25_S2 - 1.2v
PP3v3_S2_UPC - 3.3v
PP5v_S2 - 5v
PP3v3_UPC0_LDO - 3.3v
PP3v3_UPC1_LDO - 3.3v
PP1v5_UPC0_LDO_CORE - 1.5v
PP1v5_UPC1_LDO_CORE - 1.5v

Here are some measurements I am able to check before it cycles off.

Any help would be appreciated. Thanks again.
 

2informaticos

Administrator
Staff member
All USB-C ports have the same behavior?

Looks like machine tries to boot and overcurrent is detected and gets blocked.
Disconnect all, and test the board alone; only USB-C charger connected.
Also try SMC bypass.
 

bls951

New member
Yes, same thing for both ports.

I tried both your suggestions but it's the same issue. It still boot loops.
 

2informaticos

Administrator
Staff member
Probably broken traces, or solders.
Check for short, or pulsing voltage on big coils and other power rails.
 

user54321

New member
Hello!

New to this forum, but have almost same symptoms on 820-02016 board, was wondering if you found the issue.
This one does 5V 200mA for a short time, then goes down to ~40mA before shutting down and starting the cycle anew.
Measured the mentioned points aswell:

PP3V8_AON_VDDMAIN - ~3.8v
PPBUS_AON -12.3V then 12.0V and going down during reset
PPVDD_SOC_S1 - ~0.67v
PP1V8_S2 - ~1.8v
PP2V5_AWAKE_NAND - 2.5v
PP1V25_S2 - 1.22v
PP3v3_S2_UPC - 3.28v
PP5v_S2 - 5.2V
PP3v3_UPC0_LDO - 3.25v
PP3v3_UPC1_LDO - 3.25v
PP1v5_UPC0_LDO_CORE - ~1.5v
PP1v5_UPC1_LDO_CORE - ~1.5v
They are almost all pretty much the same as yours.
I found this rewa video and was wondering if it was this issue?

The voltage and amp reading are kinda off, due to them using some weird 20V -> USB-C adapterbrick.

 
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