820-01598 no power

[Kyle93]

Arrived with minor liquid damage and stuck at 5v. CD3217 LDOs are good.

PPBUS_G3H 12.30V PP3V3_G3H 3.3V

LPS2R and AWAKE voltages are all 0v not shorted.

L7806-L7809 around U7800 are all OL diode mode

LDO_RTC 0v

Does this sound like bad U7800??? Should anything else be checked?

 

[Kyle93]

PP3V3_S5 is only 0.250V but cant find what creates it on schematic. Not shorted .380 diode mode

 

[2informaticos]

Do not expect 3V3_S5 yet; U7800 is not working, nor T2.

Check R7900...

 

[Kyle93]

R7900 1ohm 0V

 

[Kyle93]

U7650 missing enable.

P5VG3S_EN 0v

 

[2informaticos]

"PP3V3_G3H 3.3V"
Do you mean 3V3_G3H_RTC?
R7900 is connected there, but doesn't get voltage...

 

[Kyle93]

PP3V3_G3H actually 0v

I mixed up measurement with the present PP3V3 _LDO

 

[Kyle93]

Looks like a bad U6903. CHGR_EN_MVR was 0v and shorted. Replaced U7000

CHGR_EN_MVR now present 5v PPVIN_G3H present 12.30V PP3V3_G3H still 0v

Replaced U6903 from donar but no change. Also changed C6903.

Ordered some replacement TPS chipsets will update once replaced again.

 

[2informaticos]

Did you check C6900 voltage?
Be sure R6900 is good; also check R6907.

Diode mode to ground at L6900?

 

[Kyle93]

C6900 12.30V

R6900 and R6907 are good

diode mode L69000.340

 

[2informaticos]

Check all R6910-13 and traces.
If all good, change U6903 again.