820-02020 no power

[Kyle93]

No liquid damage. Both ports are 5v 0.18a drops to 0.02amps then loops over. At times unplugging and plugging back in 20v will appear for a few seconds. PPBUS_G3H starts at 12.30v then 12V before looping.

Only getting 5v at PPDCIN_AON_CHGR so replaced U5200 after checking R5221/R5222/R5261/R5262 were good.

Nothing has changed. Not sure what to check next?

 

[2informaticos]

Did you check diode mode at PPBUS/3V8_AON rails?
Remove F5200 and check C5250 voltage.

Post U5200 basic voltages; P_IN, AUX_DET, SMC_RST_IN, VDDA/P, EN_MVR, AUX_OK, A/BMON.

 

[Kyle93]

PPBUS 0.490

3V8_aon 0.380

3v8_AON_ATC_ISNS .340

3V8_AON_DFR_ISNS .340

3V8_AON_MPMU_ISNS_VIN .340

3V8_AON_SPMU_ISNS_VIN .340

C250 12.30V with F5200 removed

P_IN 5V

AUX_DET 2.1V

CHGR_RST_IN 0V

VDDA 5.15V

VDDP 5V

EN_MVR 5V

AUX_OK 1.77V

AMON 0.36V

BMON 0V

 

[2informaticos]

Do you get 3V8_AON and U8100 LDOs?

 

[Kyle93]

3V8_AON 3.8V

All U8100 LDO's loop every few seconds

 

[2informaticos]

Check resistance (ohm scale) over C5220.
Also check diode mode to ground on all coils of U7700/8100.

 

[Kyle93]

resistance over c5220 is in the millions

Diode mode to ground on U8100/U7700 found no shorts.

usbc port with UF400 cycles on and off every few seconds. No shorts and both 1.5v and 3.3v LDO's are present

 

[2informaticos]

PP3V8_AON_MPMU_ISNS_VIN is stable?
If not, check RD610 and its traces.
If yes, then all PP1V5_VLDOINT_MPMU, PP1V2_S2, PP3V3_S2_UPC, PP1V8_AON_MPMU and MPMU_VREF_ADC must be stable.
Unless MPMU detects an overcurrent/short.

 

[Kyle93]

PP1V5_VLDOINT_MPMU, PP1V2_S2, PP3V3_S2_UPC, PP1V8_AON_MPMU are stable however MPMU_VREF_ADC is 0v but not shorted.

PP3V8_AON_MPMU_ISNS_VIN is stable as well

 

[2informaticos]

You've said before all U8100 LDOs loop.

No idea when MPMU_VREF_ADC should come on; compare with good board.

Now check U7700 LDOs...

 

[Kyle93]

buck4_lx0 and PP1V06_SW_DRAM appear to be shorted . 0.43 diode mode on good board but only 0.012 on this board.

Tried injecting 1v but nothing gets hot

 

[2informaticos]

0.012 isn't low enough to heat something when inject voltage.
Lift L7440/1 and R770A; check where the low value remains.

 

[Kyle93]

short remains on pad 2 of L7740. Removed every cap on the line but no change. Does this sound like a shorted M1 now?

 

[2informaticos]

Before M1, remove U7700 and check again.

 

[Kyle93]

Short remains with U7700 removed

 

[2informaticos]

Then no doubt, bad M1...