00840 5volts on both ports

[captainmac]

hey there, I am not the greatest with USBC boards, and this issue in particular drives me nuts everytime.
Currently i have 2 boards showing this exact symptom:
when charger is connected i get 5.17V (steady) on both ports, and 0Amps draw.
PPBUS is missing (0V) and not shorted to ground, no shorted highside cpu mosfets.
PP3V3_G3H is fine (3.34v) and reaches the pads under the CD3215s
I get all LDO voltages on the CD3215s, except I don't get the PP1V1_UPC_XA_LDO_BMC rail.

So far on both boards i have tried reworking and replacing the U2890 and the USB redriver chip next to the ports as well as the ISL9239 (the latter more out of desperation)
Also replaced the CD3215s multiple times (always in pairs, and these boards need the C00 chips, so that's what i've used)

Is a missing PP1V1 LDO caused by a bad CD3215, and am i just being extremely unlucky and keep putting bad CD3215s on the board?
There is only one cap on this LDO rail and that cap is fine (i.e. not shorted or no fucked pads)

Am i missing something? I haven't posted a lot of measurements, i know, but i'm off work now till after the weekend, so can get back with more measurements.

Thanks in advance!

 

[2informaticos]

"replacing the U2890"
I hope you've soldered one from exact same board model.
That is USB ROM chip; it has firmware!

Check diode mode to ground at 1V1 LDO output and compare with similar board.

 

[captainmac]

I used a U2890 from an 820-00840-01 (whereas my board is 820-00840-A), will that make a difference?

Diode mode to ground on 1v1 LDO is 0.453 on both CD3215s on the bad board.
on a known-good one (also a 00840-A) it is 0.448, so this seems fine, right?

 

[2informaticos]

Doesn't look low.
But is LDO output and should appear with 5V at USB-C input I think.
Do a search on the forum and check if is possible to confirm that on other posts.

 

[captainmac]

yeah I think that's true. I have checked a working board and the 1v1 LDO (along with all other Vouts of the CD3215) comes on immediately after connecting charger, while it is still in the 5v mode.
Geezzz does that mean I should try another set of CD3215s? or is there something else left to check first?

 

[2informaticos]

1V1 LDO output was missing on both chips in first stage?
Did you try the 4 way connections possible for USB-C charger?

 

[captainmac]

yes, it's missing on both CD3215s.
In the meantime, i have replaced both of them again on one of the boards, but still getting no 1v1 out..
And, yes i have tried all 4 orientations of the connector.

All other LDOs are working at the proper voltages on each CD3215.

 

[2informaticos]

Try removing redriver chip...

 

[captainmac]

Just tried it without the redriver.
no change. still taking 5.17v at 0amps on all four connector orientations.
I'm waiting on a new batch of CD3215s and some donorboards that are coming in next week, but this is the third set of CD3215s I've put on, can't imagine I have so much bad luck on two boards simultaneously

 

[2informaticos]

You MUST get all LDO voltages from CD3215 chips; with just 5V on corresponding USB-C port.
I've just got the confirmation from 00239 board.

 

[captainmac]

Yes, that's what I confirmed on the working 00840-board yesterday as well.
So for now, the conclusion is that the CD3215 is bad? or is there any condition required before this LDO is created? I can't figure it out from the schematics really..

 

[2informaticos]

Check each fuse close to CD3215 chip.
Post voltage for (free) pads of C3120/21 and C3220/21.
Don't make short there, or you can fry CD3215...

 

[captainmac]

OK, finally had time to get back to this one, loads of other junk to get out of the way first..

F3000/3010 Fuses are checked and ok.

When charger connected to port A:
C3120 pad 1: 5.20V / pad 2: 7.49V
C3121 pad 1: 5.19V / pad 2: 10.97V

Charger connected to port B:
C3220 pad 1: 5.20V / pad 2: 7.26V
C3221 pad 1: 5.19V / pad 2: 10.94V

 

[2informaticos]

So Q3100/200 are correctly controlled.

You must get all LDO voltages.
If no short on any, shpuld be CD3215 issue...

 

[captainmac]

Jesus I have another couple of these with only missing LDO being the 1v1 BMC one.
I have a hunch that this is a sign of bad CD3215s.
Need to find better sellers. Anyone have any good sources for the C00 version (apart from Louis obviously)

 

[Yoel Ren]

Hello captainmac, I also have this symptomps, any progress/ update? I have replaced a total of 6 chip, doesnt looks like a cd3215 failure to me

 

[captainmac]

no update yet. the only constant is that I'm using preballed CD3215s from Ali. I have run out of donors and my orders are taking too long.
What kind of chips are you using?

 

[Yoel Ren]

Im using donor cd3215coo in the form of chicken wings like rossmann, bought it from ali too...
In my case, i don't have 20v on dc in, but if i put battery, it can turn on and boot normally, only cannot charge.., maybe you can check if it does turn on with charged battery?

 

[captainmac]

yeah, mine arent turning on on battery only.

 

[Fanfwe]

Hi guys,
I was just checking if you made any progress with this issue ?
I happen to have a board with the exact same issue. One of the CD3215s gives me no 1V1. I have replaced it 3 times now, with chips I purchased reballed from different vendors on Ali. I also replaced the other CD3215 on that side of the board, just in case.
The LDO output is not shorted to ground on the PCB (measured while CD3215 was removed).
I had a look at the datasheet for TPS65986 (closest chip to the CD3215), but nothing in there really telling the criteria for that LDO to turn on during the chip power-up sequence