820-00244 no power

[Kyle93]

Arrived with no power. Client claimed liquid damage but no corrosion was found on the board. Discovered Diode mode reading lower then a good board on PPBUS_LIO. When U3100 is replaced, diode mode reading is normal again however once power is applied the same lower reading occurs. Board uses 5v 0amps.

Also tried to replace U7000 but no change

pp3v3_g3h 0v

Trying to fix for data recovery

 

[2informaticos]

Did you try another power flex?

 

[Kyle93]

yes

 

[2informaticos]

Allow 10-30s once power is removed; still short?

 

[Kyle93]

yes

 

[Kyle93]

diode mode 0.170 instead of 0.420

 

[2informaticos]

That is no short and value looks good for CD3215 chip.

Check diode mode to ground at PPBUS_G3H, 3V3_G3H and other coils.
Remove F7040 and check C7043 voltage.

 

[Kyle93]

PPBUS_G3H 0.410
3V3_G3H 0.345
L8020 0.401
L7030 0.430
L76700.325


C7043 0V with F7040 removed

 

[2informaticos]

Post U7000's basic voltages; P_IN, SMC_RST*, SMC_RST_IN, VR_AON, VDDA/P, LDO_3P0/5P0, AC_OK, A/BMON.

 

[Kyle93]

p_in 5.18v

SMC_RST* 0.485v

SMC_RST_IN 0v


VR_AON 2.995v

VDDA 4.73v

VDDP 4.95V

LDO_3P0 2.995V

LDO__5P0 4.95V

AC_OK, 0V

A/BMON 0V/0V

 

[2informaticos]

I forgot to mention ACIN...

 

[Kyle93]

CHGR_ACIN 1.280V

 

[2informaticos]

Change U7000...

 

[Kyle93]

changed u7000 from donor board but no change. Still 5v 0 amp

 

[2informaticos]

Still missing 3V3_G3H?

 

[Kyle93]

yes 0v

 

[Kyle93]

When first plugged in PPVIN_G3H_P3VG3H is 1.085v but after a few seconds slowly drops to 0v

 

[2informaticos]

Actual diode mode to ground?

 

[Kyle93]

0.344

 

[Kyle93]

What should be checked next?