(347) 552-2258 [email protected]

820-00840 Anormal Q3100

D

DavutAmana

Member
Hello,

I have this A1708 board which does not go up to 20V
The USB-C controller area is clean

The u2800 area very damaged, I replaced U2800 and do some retrofitting, now very clean

Now I have these abnormal measurements:
Q3100
PPDCIN_G3H = 5V (GOOD)
UPC_XA_GATE1 = 7.25V (NOT GOOD)
UPC_XA_GATE2 = 10V (NOT GOOD)
Q3200
PPDCIN_G3H = 5V (GOOD)
UPC_XB_GATE1 = 5V (GOOD)
UPC_XB_GATE2 = 0V (NOT GOOD)

LDO rails are good

Changing U3100 and U3200 seems like a solution to me, but I would like to know your opinion to avoid wasting time.

Thanks in advance
 
P

piernov

Moderator
Staff member
Measuring voltages on Q3200 with USB-C connected to the corresponding port right?
Start by measuring voltage on the 4 LDOs of each CD3215 (USB-C connected to corresponding port).
 
D

DavutAmana

Member
Thank you for your fast reply :)

When I plug into USB-C A I get:
CD3215 (U3200):
PP3V3_UPC_XB_LDO = 3.3V (OK)
PP1V8_UPC_XB_LDOA = 1.8V (OK)
PP1V8_UPC_XB_LDOD = 1.8V (OK)
PP1V1_UPC_XB_LDO_BMC = 0V (I THINK OK?)
PP3V3_UPC_XA_LDO = 3.3V (OK)
PP1V8_UPC_XA_LDOA = 1.8V (OK)
PP1V8_UPC_XA_LDOD = 1.8V (OK)
PP1V1_UPC_XA_LDO_BMC = 0V (I THINK OK?)
Q3100:
PPDCIN_G3H = 5V (OK)
UPC_XA_GATE1 = 7.25V (NOT OK)
UPC_XA_GATE2 = 10V (NOT OK)
Q3200:
PPDCIN_G3H = 5V (OK)
UPC_XB_GATE1 = 5V (OK)
UPC_XB_GATE2 = 0V (NOT OK)

When I plug into USB-C B I get:
CD3215 (U3200): the same voltage
Q3100:
PPDCIN_G3H = 5V
UPC_XA_GATE1 = 5V
UPC_XA_GATE2 = 0V
Q3200:
PPDCIN_G3H = 5V
UPC_XB_GATE1 = 7.5V
UPC_XB_GATE2 = 10V

I have 2 board with this identical problem.
 
P

piernov

Moderator
Staff member
1.1V LDO BMC is at least a problem. If it's not present the circuit for USB-PD negotiation in the CD3215 won't work.
On A1708, U3200 is the master and U3100 is the slave. There is a chance the issue is with U3200, or there is a communication issue between U3200 and U2890. More info here: https://logi.wiki/index.php/CD3215_Bootup_Sequence .

Measure diode mode to ground on the 4 LDOs of both CD3215 to try to see if there's a problem.
 
2informaticos

2informaticos

Administrator
Staff member
It does not appear on schematic, nor boardview.
Very close to USB connector, opposite side of CD3215 chips; look for PI3USB32224 chip.
 
You must log in or register to reply here.
Top