A2485 no power

[2try’s]

Hi, I have 820-02100 board that not powering on. It shows 5v 0.013A on usb-c amp meter. It was liquid damage in UC260 area, and I have already found 2 shorts on pp5v_s2_main and fixed it but it didn’t help. I guess that now CD3217 is not speaking with U5200 so 20v is not boosting.

PPBUS_AON - 0.018v
PP3V3_AON - 0v
PP3V3_S2 - 0.01v
PP5V_S2_MAIN - 0v
PP3V8_AON - 0v
PP1V8_AON - 0v

 

[2informaticos]

You can't expect anything to work on the board, before getting PPBUS_AON.
First, check it in diode mode.
Next, remove both F5200/1 and check C5250 voltage.

 

[2try’s]

PPBUS_AON - 0.480 diode mode
C5250 - 0.410v

 

[2informaticos]

Post U5200's basic voltages: P_IN, AUX_DET, SMC_RST_IN, VDDA/P, SMC_RST*, EN_MVR, AUX_OK, A/BMON.

 

[2try’s]

PPDCIN_AON_CHGR_R - 5.257v
CHGR_AUX_DET - 0.863v
CHGR_RST_IN - 0.035-0.038v
PPCHGR_VDDA/P - 5.134v
P3V8AON_PWR_EN - 0v
CHGR_AUX_OK - 0v
CHGR_AMON/BMON - 0v
SMC_RST* shows as unconnected in my boardview

 

[2informaticos]

Looks like bad U5200.
Be sure all surrounding components and traces are good.

 

[2try’s]

Surrounding components and traces looks ok. I already suspected U5200 but replasing didn't give any result, only small chanches in ampmeter - 0.015-17A instead of 0.013-14