CD3215 Bootup Sequence

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Getting 20V on the charger

A1706 USB-C Sequence.jpg

If a CD3215 does not have the LDO outputs, test the lines for shorts, otherwise the chip is missing power or bad. Data sheet of closest Ti chip.

A bad CD3215 can often cause a loop at step 10. All of the CD3215s need to be fully functional and communicate with the SMC before the CD3215 connected to the charger will request 20V.

The TBT ROM is required to get to 20V. It is powered by the CD3215 on the opposite side. It will not boot unless it can communicate. It seems with liquid in that area, the trace between the LDO of the CD3215 and TBT ROM gets damaged at the test point.

Please note, the chip designations and net names are from an A1706.

Steps Before 20V on Charger
Step Source Name of Net Voltage
2 U3200 PP3V3_UPC_XB_LDO 3.3V
3 U3200 HV_GATE1 High(5v, later 20V)
U3200 HV_GATE2 High(5v, later 20V)
4 Q3200 PPDCIN_G3H 5V
5 U7000 TBA_VDDA 5V
6 U7000 PM_EN_P3V3_G3H 3.3V (5V on many boards)
7 U6903 PP3V3_G3H 3.3V
8 U5000 PP1V2_G3H_SMC_VDDC 1.2V
9 U5165 PP3V0_G3H_AVREF_SMC 3.0V
10 U5000 SMBUS_SMC_4_G3H_SCL 3.3V (clock)
U5000 SMBUS_SMC_4_G3H_SDA 3.3V (data)
11 U3200 USB_XB_CC1 0.8V (data) (verify)
U3200 USB_XB_CC2 0.8V (data) (verify)
12 J3300 PP20V_USBC_XB_VBUS 20V
13 J3300 HV_GATE1 >20V
J3300 HV_GATE2 >20V
14 Q3200 PPDCIN_G3H 20V
15 R7015 TBA_AUX_DET 5V
16 U7000 SMC_RST_L 3.3 (verify)
17 U7000 Q7030 Q7040 opening Unknown (low maybe)

Booting fully

Thunderbolt isnt required to get 20V.

If you get a message saying Critical Update Required there may be a problem with the logic board.