MBA 820-01521-A Missing PP5V_G3S

[MobileXT]

Hello, I am working on a board that has no water damage just died and only have 5v on the charger. I do have PP1V8_SLP2R present, PP3V3_G3H_RTC Present and PHV_INT_XA_G3H Present. Missing PP5V_G3S. Where is this power generated? from CD3215 or U7100? I need your help please. Thanks.

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

Power is generated by the external power adapter. It will start off by default @ 5V and provided that each CD3215 is working properly, only then can they negotiate with the external power adapter to supply the 20V power delivery contract. Respectively, it is vital that the CD3215 are functioning properly.

What is the voltage for PPBUS_G3H ?

Measure @ C7050 on the logic board. Meter in 20V DC scale.

Red meter probe to C7050 (+) = pin # 1. Black meter probe to ground (shield) or can be pin # 2 on the same capacitor or convenient cluster of caps in the same group.

[MobileXT]

Re: MBA 820-01521-A Missing PP5V_G3S

Power is generated by the external power adapter. It will start off by default @ 5V and provided that each CD3215 is working properly, only then can they negotiate with the external power adapter to supply the 20V power delivery contract. Respectively, it is vital that the CD3215 are functioning properly.

What is the voltage for PPBUS_G3H ?

Measure @ C7050 on the logic board. Meter in 20V DC scale. 12.33v

Red meter probe to C7050 (+) = pin # 1. Black meter probe to ground (shield) or can be pin # 2 on the same capacitor or convenient cluster of caps in the same group.

C7050 PIN1= 333k Ohms red on +

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

PP5V_G3S is created by U7650.

Remove all power. Meter in resistance mode (2k scale).

Check & post the resistance to ground for L7670 (either side). Checking for a low resistance value which will likely lead to a bad (shorted) cap. This will cause an excessive current draw and force this regulator to shut down.

If the resistance is not very low, then proceed to use the meter in DC volts mode (20V DC scale).

Measure & post the voltage for:

P5VG3S_EN_DLY

P5VG3S_EN


L7690

PP3V3_G3H

U7650 is responsible for 2 voltage rails. You have confirmed that at least one side is not working as expected. Confirm the ENABLE is present for this missing rail.

While there, check the right side rail as well to see if it is working.

[MobileXT]

Re: MBA 820-01521-A Missing PP5V_G3S

PP5V_G3S is created by U7650.

Remove all power. Meter in resistance mode (2k scale).

Check & post the resistance to ground for L7670 (either side). Checking for a low resistance value which will likely lead to a bad (shorted) cap. This will cause an excessive current draw and force this regulator to shut down.

If the resistance is not very low, then proceed to use the meter in DC volts mode (20V DC scale).

Measure & post the voltage for:

P5VG3S_EN_DLY =0v

P5VG3S_EN = 0V


L7690 3.3v no shorted on L7670 = 0v

PP3V3_G3H = 3v3

U7650 is responsible for 2 voltage rails. You have confirmed that at least one side is not working as expected. Confirm the ENABLE is present for this missing rail.

While there, check the right side rail as well to see if it is working.

No shorted on L7690 and L7670
L7690 = 3.3v
L7670= 0v. no short.

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

Hi I am also working on an 820-01521 that has no PP5V_G3S. U7650 is not getting enable signal for this voltage. It looks like that EN should come from PMIC U7800. Any further news on this repair please @MobileXT ?

Thanks I know it's probably best to make a new post but this one isn't that old so I thought I would just piggyback on here.

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

What is the voltage of

P5VG3S_EN @ R7613, pin # 1 ?

P5VG3S_EN_R @ R7613, pin # 2 ?

Remove all power. No battery. Meter in resistance mode.

What is the resistance to ground of P5VG3S_EN @ R7613, pin # 1 ?

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

What is the voltage of . . . . etc

I realise that this is the other guys post but he is MIA I would greatly appreciate any help please @mon2

* I have 0v both sides of R7613 (working board is 1.79v)

* R7613 measures 0.7Ω (should be 0Ω but probably just resistance of DMM leads?)

* RTG of P5VG3S_EN is 46K (working board is 46K also)

* P5VG3S_EN comes from PMIC U7800 so am I screwed

PS - I tried DFU restore / revive but board wouldn't go into DFU mode

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

What is the voltage of PPBUS_G3H ?

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

What is the voltage of PPBUS_G3H ?

Sorry for the delay but I have now turned on thread notifications.

PPBUS_G3H - 12.64v 20v / 0.03A on charger and seeing what else I have or am missing.

PP3V3_G3H - 3.3V

PP5VG3S - 0.029V diode 0.441 so no short
P5VG3S_EN_DLY - 0v
this comes from U7610 which has its
PP3V3_G3H supply at 3.3v
but no P5VG3S_EN_R (diode 0.540 so no short) which also comes from U7800

P5VG3S_PGOOD - 1.75v

P1V8G3S - 0v
P1V8G3S_EN - 0.560 so no short


Pointing to PMIC/T2 issues?

I also forced into DFU mode (1v8v into SOC_FORCE_DFU) but it timed out and would't complete. I tried twice but cannot recall the exact error. Suffice to say that isn't going to fix it

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

Use the exact net names from the schematics. It will make the review much easier to follow.

P5VG3S_PGOOD - 1.75v
P1V8G3S - 0v (correction: PP1V8_G3S)

This does not look correct.

PGOOD signals are open-drain lines. There will be a logic low but no logic high. Instead, '1' state will be high impedance and demands a local pull-up.

The pull-up here is R7600. The other side of R7600 should be 1v8 (PP1V8_G3S).

You have 1v75 yet the PP1V8_G3S = 0v ??

Confirm the voltage of PP1V8_G3S.

Also remove all power, confirm the resistance of R7600. Measurement ?

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

Apologies for the sloppy net names @mon2

Yes I see what you are saying now.

PP1V8_G3S is indeed 0v diode 0.344

R7600 is 99.7Ω so within spec.

I rechecked all my other readings and they are all good, both voltages and diode reading.

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

What is the voltage of P5VG3S_PGOOD ?

PP1V8_G3S is indeed 0v diode 0.344

Measure at the resistor R7600.

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

That is the voltage measured at R7600.

Diode value 0.344v refers to diode mode measurement of that line PP1V8_G3S

P5VG3S_PGOOD is 0v too

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

In post #10, you had 1v75 for this signal. No more?

Remove all power, meter in resistance mode.

Check the resistance to ground of P5VG3S_PGOOD.

Post the measurement and meter scale used for the measurement.

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

Yes sorry post #10 was a mistake. I had three of these boards going at once and I got confused

P5VG3S_PGOOD resistance to GND is 595K ohms on auto ranging scale.

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

Check and post each SLPS2R and AWAKE rail voltage:

PP1V8_SLPS2R
PP1V1_SLPS2R
PP0V8_SLPS2R

PP1V2_AWAKE
PP3V3_AWAKE

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

Pin 1 (PP1V8_SLPS2R) of R4519 is a steady 1.8v but PP1V8_SLPS2R_SOC_LPOSC_RC (pin 2 of R4519) is only 0.628v (should be 1.8v)

R4519 is correct value at 49.9Ω

In regard to your questions, I have all those voltages.

PP1V8_SLPS2R - 1.8v
PP1V1_SLPS2R - 1.1v
PP0V8_SLPS2R - 0.8v

PP1V2_AWAKE - 1.2v
PP3V3_AWAKE - 3.3v

[mon2]

Re: MBA 820-01521-A Missing PP5V_G3S

Pin 1 (PP1V8_SLPS2R) of R4519 is a steady 1.8v but PP1V8_SLPS2R_SOC_LPOSC_RC (pin 2 of R4519) is only 0.628v (should be 1.8v)

R4519 is correct value at 49.9Ω

PP1V8_SLPS2R_SOC_LPOSC_RC is not at the correct value.

Remove all power. Meter in resistance mode. Check the resistance to ground of PP1V8_SLPS2R_SOC_LPOSC_RC.

What is the voltage of PP1V8_SLPS2R_SOC_LPADC_RC ?

[Pedro147]

Re: MBA 820-01521-A Missing PP5V_G3S

resistance to ground of PP1V8_SLPS2R_SOC_LPOSC_RC - 63.3Ω

voltage of PP1V8_SLPS2R_SOC_LPADC_RC - 1.8v