(347) 552-2258 help@rossmanngroup.com

A2442 - 820-02098A 5V 3mA-0mA

J

jadao

Member
Got this board for repair, 5V 3mA for a couple of seconds then 5V 0mA. it had a tiny spot of liquid damage on C7768 (PP1V2_AON_SPMU pad corroded gone ) and C7780 (PP1V5_AON_VCORE_SPMU pad corroded gone).

PPBUS_AON: 12.29v
PP3V8_AON: 3.8v
PP3V8_AON_MPMU_ISNS: 3.8v
PP1V2_S2: 0V / 0.231

PP3V3_S2: Unstable 3.3V to 1.25V / diode mode value: 0.376
PP1V8_S2SW_CLVR_VDDC1_LDO: Unstable 1.8V to 0.5V / diode mode value: 0.492
PP3V3_AON: Unstable 3.3 to 0V / diode mode value: 0.375
PP0V8_S2_CLVR_VDDDIG: Unstable 0.8V / diode mode value 0.289
PP1V8_AON: 1.8V
PP1V2_AON: 1.2V
PP1V5_AON_VCORE_MPMU: 1.5V

PMU_VDDHI: 2.584V

I replaced U8100 from same donnour board and I got exactly same results...
I compared coils diode value around U8100 and U7700 with donnour board and they are the same. I also see no voltage on any coil around u7700.

Damage affected 2 signals PP1V2_AON_SPMU and PP1V5_AON_VCORE_SPMU coming right from U7700, but I have no way to test them for shorts because pads are gone on the filter capacitors...
 
J

jadao

Member
You are right, despite liquid damage was exactly on the other side of SPMU board, I thought PP3V_AON unstable must have to do with (mpmu) U8100. I should have asked before.
Now I am exactly at square one, I was going to replace spmu but wanted to ask if any other conditions to check before reballing a replacement one…
Thks
 
J

jadao

Member
Voltage / Diode mode value
I have exactly same reading before and after replacing U8100.
Thanks

U8100 LDOS:

VIN_LDO1=VIN_LDO2=VIN_LDO4=VIN_LDO1V8=VIN_LDO1V2=VIN_VCORE=PP3V8_AON_MPMU_ISNS: 12.29V / 0.174
VIN_LDO5=PP1V2_S2: unstable 0-0.4V / 0.231

VLDO1 : PP3V3_S2: Unstable 3.3V to 1.25V / 0.376
VLDO2 : PP1V8_S2SW_CLVR_VDDC1_LDO: Unstable 1.8V to 0.5V / 0.492
VLDO4 : PP3V3_AON: Unstable 3.3 to 0V / 0.375
VLDO5 : PP0V8_S2_CLVR_VDDDIG: Unstable 0.8V / 0.289
VLDO1V8 : PP1V8_AON: 1.8V / 0.426
VLDO1V2 : PP1V2_AON: 1.2V/ 0.592
VCORE: PP1V5_AON_VCORE_MPMU: 1.5V / 0.368

U7700 LDOS:

VIN_LDO0=PP1V2_S2 : unstable 0-0.4V / 0.234
VIN_LDO3=PP1V8_S2 : 0V / 0.235
VIN_LDO1V8=VIN_LDO1V2=VIN_VCORE=PP3V8_AON_SPMU_ISNS : 3.8V / 0.174

VLDO0 : PP0V72_S2_VDDLOW: 0V / 0.239
VLDO3 : PP1V2_AWAKESW_BLC: 0V / 0.669
VLDO1V8 : PP1V8_AON_SPMU: 1.8V / 0.516
VLDO1V2 : PP1V2_AON_SPMU: can't measure, no more pad under the cap.
VCORE: PP1V5_AON_VCORE_SPMU: 1.5V / 0.385

U8100 BUCKS:

BUCK0 PPVDD_ECPU_AWAKE L8200@L8203 : 0V / 0.116
BUCK1 PPVDD_GPU_BMPR_S1 L8210@L8211 : 0V / 0.253
BUCK2 PPVDD_ECPU_SRAM_AWAKE L8220 : 0V / 0.378
BUCK3 PP1V8_S2SW L8230 : unstable 0-0.08V / 0.289
BUCK4 PPVDD2H1_S2SW L8240@L8243 : unstable 0-0.4V / 0.062
BUCK5 PPVDD_AVEMSR_AWAKESW L8250@L8253 : 0V / 0.125
BUCK6 PPVDD_AMPH1_S2SW L8260: unstable 0-0.4V /0.400
BUCK7 PP0V81_S1_SRAM L8270@L8272: 0V / 0.180
BUCK8 PP1V2_S2 L8280: unstable 0-0.4V / 0.234
BUCK9 PPVDD_FIXED_S1 L8290 : 0V / 0.181
BUCK10 PP0V575_S1_VDDQ1 L82A0@L82A1 : 0V / 0.116

U7700 BUCKS:

BUCK11 PPVDD_SOC_S1 L7850@L7853 : 0V / 0.030
BUCK12 PP1V2_AWAKE L7880 : 0V / 0.223
BUCK13 PP0V575_S1_VDDQ0 L7810@L7811 : 0V / 0.113
BUCK14 PPVDD2H0_S2SW l7840@L7843 : 0V / 0.063
BUCK16 PP0V855_S2SW_VDDCIO L7860: 0V / 0.180
BUCK17 PPVDD_DCS_S1 L7800@L7803: 0V / 0.135
BUCK18 PP0V95_S2SW_VDD2L L7820: 0V / 0.312
BUCK19 PP1V8_S2 L7830: 0V / 0.230
BUCK20 PPVDD_DISP_AWAKESW L78A0@L78A2 : 0V / 0.044
BUCK21 PPVDD_AMPH0_S2SW L7890 : 0V / 0.398
 
You must log in or register to reply here.
Top