820-00840 5v on both ports, 0v on PP1V1_UPC_X/A/B_LDO_BMC

[No-Clean]

Clean board overall, had some small corrosion near C3208 and R3203, after cleaning the area and reflowing CD3215 same problem, only 5.2v and 0.02a taken.

I then replaced first the CD3215 that was next to the corrosion and same thing, then replaced the other CD3215 and same thing, those were purchased from Rossmann I sure there are good and both are the C00 ones.

No shorts, but PP1V1_UPC_XA_LDO_BMC and PP1V1_UPC_XB_LDO_BMC are both 0 volts, I connected the charger in all 4 ways, diode mode to ground on those lines are 0.496 and 0.512.

F30000 and F3010 are both fine.

I also checked redriver and looked fine, but removed it to test anyways but same problem, I am still learning about this USB-C boards and I am having a hard time with them.

 

[2informaticos]

Post 3V3_G3H and R7020 voltages.
Also check TBA_AUX_DET, TBA_VDDA/P, SMC_RESET_L and BUF_SMC_RESET_L.

 

[No-Clean]

3V3_G3H 3.4v
R7020 5.2v
TBA_AUX_DET 1.3v
TBA_VDDA 5.1v
TBA_VDDP 5.1v
SMC_RESET_L 3.4v
BUF_SMC_RESET_L. 3.4v

​

 

[2informaticos]

I had 00840/00875 boards where I got 1.1V LDO output only from one CD3215.
Sometime I did a trick on the port with missing voltage and it worked; but never worked when both chips missed 1.1V LDO.
I suppose you still have a problem with USB-C area; maybe corrosion around U2800/90.

 

[No-Clean]

U2800 looks perfect, I checked for shorts and bad resistors around it and found nothing.
U2890 I tried a different one from a -01 board but no luck.

I just also tried 2 new CD3215 and nothing either.

I wonder if TCRScircuit can give us some tips.

 

[2informaticos]

Put back original U2890; make backup dump first.
Can you see any activity on its pins, with o-scope?

 

[captainmac]

following.. still havent figured this out either

 

[Yoel Ren]

I have this exact problem.. No solution so far

 

[captainmac]

OK, just wanted to let you know i have resolved all of these with a missing BMC LDO by replacing the TBT ROM (U2890 on a 00840 board). In all of them, the BMC LDOs came back and i got 20v back.

 

[2informaticos]

Thanks for mention.
Did you make a backup of working ROM?
Flashing original chip should be sufficient in such case...