820-01041-A NO POWER

2click

Member
This board had little liquid damage, and its not turning on,
ppbus_g3h = 12.6
PP3V3_G3H_SOCPMU = 3,3
PP1V2_S3 = 0
PPVCC_S0_CPU = 0
PP5V_G3S = 5,13
PP1V5R1V35_S0_GPU_MEM = 0
PPVCORE_S0_GPU = 0
CPU_PWRGD = 0
PMU_ONOFF_R_L = 1,3
PM_SYSRST_L = 0
PM_PCH_SYS_PWROK = 0
PM_PCH_PWROK = 0
PLT_RST_L = 0
PM_RSMRST_L = 3,3
SMC_SYSRST_L = 0
PVCCIO_EN = 0

don´t know where to start... if I force DFU mode injecting 3v, it stays in 5v, is that normal?
 

2informaticos

Administrator
Staff member
The board should enter DFU, if you get all AWAKE and SLPS2R voltages.
It will stay on 5V at USB-C input then, as normal.
 

2click

Member
I was able to access it in DFU mode, the firmware was restored correctly, but never saw image on the screen, then tried to connect it to a external hdmi screen but it´s not turning on... can you please tell me which voltages are needed on the power sequence in that model? Thank you!
 

2click

Member
I dont get voltages on big coils exept for: L7030 and L7660
PP1V05_S0SW is not present on the PMU I get all the voltages but that one and I´m not sure but it seems to be created in U7800 is that right?
 

2informaticos

Administrator
Staff member
If you post so ambigous information, I cannot help :(.
You are telling to NOT get coils voltage, except two, and next line you say to get ALL VOLTAGES.
What should I understand, or how???

Which are these "all voltages" you get on the board?
If you don't get voltage on more coils than L7030/660, why would you look for an S0 voltage?

Trigger PMU_ONOFF_L and check for drop pulse at PM_SLP_S4_L (at same time).
Use SWK000/2 pads, instead of power button.
Do the same with PM_SLP_S3_L.
 

2click

Member
sorry: PP1V05_S0SW is not present on the PMU I get all PMU voltages but that one and I´m not sure but it seems to be created in U7800 is that right?
 

2click

Member
Tried triggering PMU_ONOFF_L
PM_SLP_S3_L = 0
PM_SLP_S4_L = 0

on my usb c voltage meter when I connect the computer i get this
5v transition to 20v with a .200 Amp consumption for 2 seconds then drops to 30 miliamps...
 

2informaticos

Administrator
Staff member
Did you try SMC bypass?
If is not a SMC sensor issue, then may have a short in a secondary power supply.

I hope you'checked the mentioned reactions at same time when triggering PMU_ONOFF_L.
BTW, PMU_ONOFF_L stays high normally?
 

2click

Member
I checked the reactions when connecting the usb c charger on both rails no pulse or voltage I checked them shorting PMU_ONOFF_L to ground and no pulse or voltage came out of those lines. PMU_ONOFF_L is high at 3.3v

I will try to bypass smc, just don´t know how to do it in this models...
 

2click

Member
Ok, i just tried SMC bypass and It just doesnt do anything... its the same behavior goes to 200 mAmps then drops to 30 mAmps...
 

2click

Member
Please help me understand what´s happening with this board... it is apparently trying to start but when I connect it to the USB C meter it gets to 5v @120-240 mAmps then makes the transition to 20.1v @200mAmps top and drops to 30mAmps. I think there is something wrong when it is at 5v. It shouldn´t take that high amperage at 5v, correct? Please Help me I am so stuck with this board!
 

2informaticos

Administrator
Staff member
The problem appears when the board switches to 20V.
It tries to start and probably short on a secondary power supply is detected.
Check for pulse at all big coils, when connect the charger; at the same moment when switches 5-20V.
 

2click

Member
The only 2 coils that get some voltage and have correct values are L7030 and L7660 no other coil pulses I even checked with an osciloscope and I get nothing... don´t know what to do...
 

2click

Member
I didn´t had PVDDQ_EN so I reballed U7800 just in case... the board turned on, I connected it into the case... it showed the apple and question mark folder... now I am trying to turn it on again but it won´t. It´s stuck at 5v @250-450mAmps
 
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2click

Member
All capacitors are good, replaced a couple of them, but no difference... Still not getting PVCCIO_EN and already changed U7800 this is driving me crazy... what voltages are requiered on U7800 for it to create that line?
 
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