820-0281 not turning on

[Sr. Robot]

No signs of damage except for a bit of corrosion on pins 3 and 4 of QB701.

PPDCIN_G3H_CHGR: 19.8v
PPVBAT_G3H_CHGR_REG: 0.9v (starts at 0.4v and then slowly goes up to 0.9).
PPBUS_G3H: 0.9v

 

[2informaticos]

Diode mode to ground at PPBUS_G3H?

Remove F7000/1 and check C7050 voltage.

 

[Sr. Robot]

Diode mode to ground at PPBUS_G3H : 0.330 (same as good board).

Removed F7000/1. C7050 voltage is 0v but PPBUS_G3H is still 0.9

 

[2informaticos]

Any reason to check PPBUS_G3H voltage once both fuses are removed???
Put some logic on your job.

Post U7000 basic voltages: P_IN, AUX_DET, SMC_RST_IN, VDDA/P, EN_VR1, SMC_RST*, AUX_OK, A/BMON.

 

[Sr. Robot]

P_IN: 20.06v
AUX_DET: 4.72v
SMC_RST_IN: 0v
VDDA: 5.09v
VDDP: 5.09v
EN_VR1: 5.09v
SMC_RST: 3.4v
AUX_OK: 3.4v
AMON: 0V
BMON:0V

 

[2informaticos]

Still no voltage on C7050?
In such case, check Q7030/40 and their traces and adjacent components.

Keep both F7000/1 removed.

 

[Sr. Robot]

No voltage on C7050

All Q7030/40 traces good. Surroungin caps looks good. R7020 measures 0.000 ohms

 

[2informaticos]

Then change U7000...

 

[Sr. Robot]

changed u7000, no effect

 

[2informaticos]

"All Q7030/40 traces good"
I also said to test the MOSFETs, not only traces...

 

[Sr. Robot]

I dont understand 100% how these mosfets in series work.

I get 20v on PPDCIN_G3H_CHGR

But i get 0v on the four gates TBA_GATE_Q1/Q2/Q3/Q4 and 0v on TBA_LX1/X2 and hence 0V on drain.

I tested the ISL9239 i removed and installed on a good board and it works allright

 

[2informaticos]

Still no voltage at C7050?
Test with both F7000/1 removed.

 

[Sr. Robot]

Still no voltage on C7050 with both F7000/1 removed

 

[2informaticos]

Do you get 3V3_G3H?

 

[Sr. Robot]

Yes, i get 3.4v on 3V3_G3H

 

[2informaticos]

Then your problem is U7000, an adjacent component, or trace.

 

[Sr. Robot]

I measured every line in U7000 in diode mode but its the same as good board. Replaced both Q7030/40 just in case but still nothing. Could it be the SMC?.

Here are the diode mode measurements:

	Good	Bad
TBA_GATE_Q4	0.686	0.714
TBA_VDDA	0.405	0.398
PPVBAT_G3H_CHGR_REG	0.384	0.38
TBA_CSO_P	0.386	0.38
PPVIN_G3H_P3V3G3H	0.496	0.487
TBA_LX2	0.284	0.328
TBA_BGATE	0.552	0.548
TBA_CSO_N	0.388	0.375
PPDCIN_G3H_CHGR	0.494	0.49
TBA_BOOT2	0.522	0.515
PPVBAT_G3H_CONN	0.556	0.548
CHGR_BMON	0.546	0.534
TBA_CSI_N	0.494	0.491
TBA_GATE_Q3	0.417	0.406
TBA_VDDP	0.408	0.396
TBA_AUX_DET	0.549	0.537
CHGR_AMON	0.545	0.534
TBA_CSI_P	0.494	0.491
TBA_GATE_Q2	0.416	0.405
TBA_COMP	0.547	0.536
TBA_BOOT1	0.524	0.52
PM_EN_P3V3_G3H	0.54	0.528
SMC_BC_ACOK	0.538	0.525
PP3V3_G3H	0.311	0.307
TBA_LX1	0.284	0.328
SMC_4FINGERS_RST	0.545	0.535
HPWR_EN_L	0.548	0.537
SMBUS_SMC_5_G3_SDA	0.373	0.372
TBA_GATE_Q1	0.682	0.714
SMC_CBC_ON	cant measure
SMC_CHGR_INT_L	0.537	0.528
SMC_RST_L	0.535	0.534
SMBUS_SMC_5_G3_SCL	0.372	0.378

 

[2informaticos]

Did you remove both F7000 & F7001 from MLB?

Check the resistance (ohm scale) over C7020/23.

 

[Sr. Robot]

Yes, i removed both F7000 and F7001

resistance over C7020/23 is 130k ohms

 

[Sr. Robot]

Sorry, i misunderstood the question.

resistance over C7020 is 3 ohms and C7023 is 3.3 ohms