820-01987 20V 0Amp

[raainxx]

Hi,
i have this board, I can't enter in DFU mode.
PPBUS_G3H = 12,31V
i have all SLP2R but I have all AWAKE (PP3V3_AWAKE)
is it normal?
thanks
Best regards

 

[2informaticos]

If ALL AWAKE and SLPS2R voltages are present, machine should appear in DFU.
SSD voltages also required to complete restore.
Did you follow all the stepst from DFU tutorial?
Any history fault available?

 

[raainxx]

sorry I forget a word I have all awake except PP3V3_AWAKE.
PP3V3_AWAKE is It necessary to enter in DFU?
liquid (near U6903) I reball U6903 seems good
thanks

 

[2informaticos]

3V3 AWAKE is also needed, of course.
Post diode mode to ground there.

 

[raainxx]

3V3_AWAKE in diode mode 0,612V normal.

 

[2informaticos]

Then U7800 shoud be the culprit.
Do you get all other voltages from U7800 (SYM 1 OF 4)?

 

[raainxx]

PP3V3_G3H_PMU_VDDMAIN=3,32V
PP1V8_SLPS2R=1,8V
PP3V3_G3H_RTC=3,298V
PP1V1_SLPS2R=1,105V
PP3V3_G3H_PMU_VINRTC_R=3,3V

Output:
PP0V8_SLPS2R=0,803V
PP3V_G3H_RTC=3,01V
PMU_LDO3_OUT_R=1,802V
CPU_C10_GATE_L=0,01V
PP1V_S0SW=0,09V
PP3V3_G3H_PMU_VDDMAIN=3,32V
PP3V3_AWAKE=0,020V
PP3V3_S5=0V

is it liquid spill under U7800? I haven't remove the shield, how can I do? with hot airgun?
thanks

 

[2informaticos]

If no short on 3V3_AWAKE, then U7800 has an internal problem, or broken solder.
Search on Youtube, if someone shows how to access that area.
Apply 138 degrees solder paste; it will help you a lot.