A1708 820-00840-A No power 5v 0amp

[GoobyPlzz]

Good morning,

No signs of liquid damage. When I received the board, only one of the USB-C Ports was working, I replaced the CD3215 with a correct C00 version and now both ports work. Prior to replacing the CD3215 PP3V3_G3H was at 2.1v, not it's at 4.8v. However, the device still does not turn on.

With the battery removed:

pp3v3_s5 0.1mV
pp1v8_s5g 0.0
pp3v3_G3H 4.83v
ppbus_g3h_cpu 40mV
ppbus_g3h 40.3mV
pp20v_usbc_xa_usbx-Ca_vBus_conn 5.1v
pp3v3_ldo3v - 0.6mV

I reflowed U7800 since it seemed like this would be the problem area, but still no dice. Any help appreciated. Thank you

 

[2informaticos]

"pp3v3_G3H 4.83v"
Big problem there; you have important overvoltage on 3V3_G3H power rail.
Check the exact values of the resistor in the feedback network (R6993-97); don't forget R/C6994.
Also check all traces in that area; pay atention to XW6995.

 

[GoobyPlzz]

R6993 - 30.6 mV
R6994 - 7.8 V (both sides)
R6995 - 3.4V (right side)
R6995 - 1.1V (left side)
R6996 -30.6 mV (right side)
R6996 - 1.013 V (left side
R6997 - 3.4V (both sides)

C6993 - 4.8V
C6994 - V3V3G3H__BST_R 7.7V
C6994 - V3V3G3H_SW 3.4V

Can't seem to find XW6995

as always, thank you for your help. Trying to figure this out.

 

[GoobyPlzz]

D6905 was the culprit, PPDCIN wasn't making contact, now that it's fixed I get 3.4v on 3V3G3H, still stuck at 5.191v 0a


Updated numbers With the battery removed:

pp3v3_s5 0.0mV
pp1v8_s5g 0.0
pp3v3_G3H 3.4V
ppbus_g3h_cpu 40mV
ppbus_g3h_s5 46.8 mV
ppbus_g3h -50mV
pp20v_usbc_xa_usbx-Ca_vBus_conn 5.1v
pp3v3_ldo3v - 0.6mV

I noticed the USB-C port that wasn't working before switching the CD3215 chip is reading PP3V3_G3H at 2.9-3.0v little lower than the other USB-C port.

 

[2informaticos]

So you never had 4.83V at 3V3_G3H?
Please, post accurate information; is your interest to save time.
You couldn't get higher voltage there with bad contact on D6905.

Both USB-C ports must have same behavior.
If not, compare diode mode readings between both channels around CD3215 chips.
Start with their LDO lines.

Check diode mode to ground at PPBUS_G3H and all big coils.
Remove F7000 and check C7050 voltage.

 

[GoobyPlzz]

Power in, no battery:
Removed F7000 C7050 was at 50mV

DIODE Readings (no power obviously)

PP1V1_UPC_XA_LDO_BMC 0 .523V
pp1V1_UPC_XB_LDO_BMC - 0.523V

XA_LDOA .530V
XB_LDOB .530V

XA_LDOD .490V
XB_LDOD .494V

PP3V3_UPC_XA_LDO .511v
PP3V3_UPC_XB_LDO .506V

PP3V3_PDO3V - .419

 

[2informaticos]

All mentioned LDOs get correct voltage?
Be aware, 1V1 LDO should appear on the powered port only.

You've forgot diode mode on PPBUS_G3H and big coils.

 

[GoobyPlzz]

I'm showing PPBUS_G3H at .403V (diode mode)

Putting F7000 back on
1V1 LDO is showing .1 mV - .2mV back and forth on both sides at the same time.

 

[2informaticos]

We still don't know if you get correct LDOs voltage on CD3215 chips.
Each one has 4 LDO lines.

 

[GoobyPlzz]

I'm going to be honest man, I don't know what exactly you're asking or telling me to look at.

What do you mean we don't know if I get the correct LDO's voltage on the CD3215 chips? I gave you the reading I found, not sure how I'm suppose to spot check that. I realize each one has 4 LDO lines, I believe i've provided all of them to you.

I understand you can't just tell me the answer as there can be many answers, but at the same time I joined this forum because I don't know how to find these things. I'm asking for guidance so I can learn.

 

[2informaticos]

"DIODE Readings (no power obviously)"
I supposed that you've posted diode readings indeed.
BTW, for the future, don't write "V" after diode readings; avoid any misunderstood.

Please, post now voltage on these LDOs.
Let see if you get all them good.
Be aware, 1V1 LDO must appear on the powered port only.

Also, did you check diode mode on the big coils?