820-02020 strange noise

bartech

Member
cpu make strange ticking noise. water damage .
usbc jumping 5,18-5,21 and 0,0A - 0,03A
ppccin-5,17V
ppchrg_vdda-5,12
ppvbat_aon_chrg_reg-5,12

death cpu?
 

bartech

Member
PPBUS_AON - 12.00v->12.28v->12,00v
3V8_AON -voltage jumping and going up and low like 0,4v->0,70v->1,50v and other values bus going up and down
 

bartech

Member
PPVDD_PMU_LDO_PREREG - diode 308 , 0v
PP1V5_VLDOINT_MPMU - diode - 240 , 0v
PP1V8_S2 - diode 337 , v 0v
PP3V8_AON_MPMU_ISNS_VIN 348 , voltage jump some like 0,14 - 0,72 - 1,61 v and go around and rising
PMU_VDD_HI diode 586, voltage same like pp3v8
PP1V25_ 2 - 276 , 0v
VSS_ANA_MPMU - short
 

2informaticos

Administrator
Staff member
VSS_ANA_MPMU is grounded by default.
You can see that on page 34.

What about SPMU side?

Check all coils around U8100 and U7700.
Also check any secondary coil on the board.
 

bartech

Member
U7700

PP3V8_AON_SPMU_ISNS_VIN - short on leg 2 - 0v , leg 1- 348 - voltage jumping circuit
PP1V5_VLDOINT_SPMU - 276 , 0v
PP3V8_AON_SPMU_ISNS_VIN 347 . voltage jumping circuit
PP5V_BSTLQ_SPMU 442 , voltage jumping circuit

short on line PP1V06_s2sw_dram
PPVDD_SOC_S1
PPVDD_PCPU_AWAKE
 

2informaticos

Administrator
Staff member
"PP3V8_AON_SPMU_ISNS_VIN - short on leg 2 - 0v , leg 1- 348 - voltage jumping circuit"
Legs 1 & 2 of who???
How can you have short on a rail coming from 3V8_AON (through 5 miliohm resistor)?

"short on line PP1V06_s2sw_dram"
What exact ohm value?
Compare with good board, if no pure short.

"PPVDD_SOC_S1
PPVDD_PCPU_AWAKE"
Short to ground also?
Ohm scale readings?
 

bartech

Member
PP3V8_AON_SPMU_ISNS_VIN - 348, voltage jumping like 0.4 v -> 1v -> 1,4 v circuit no short check wrong - sorry touched something small too...

PP1V06_s2sw_dram
PPVDD_SOC_S1
PPVDD_PCPU_AWAKE work same - 24.9 ohm on diode 30 not pure short as you write
 
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