CD3217 and T2 Power on Sequence

=== T2 power sequence checkpoints ===
Calpe PMU is a very complex chip with multiple functions and buck converters inside. There are numerous things to check before you replace it if you do not have T2 power. 
# primary power supply is PP3V3_G3H_RTC. This line is different from PP3V3_G3H supply and it is very important to understand that Calpe passes 3V3_G3H_RTC through to PP3V3_G3H before it issues PMU_VDDMAIN_EN which is a main enable signal for 3/5V regulator. It seems that it is issued once we got 20v on charger and ISL9240 switches into buck mode thus it is T2 firmware dependant.
# one of the main checkpoints to look at is Calpe LDO section(Page called PMIC LDOs in schematics). everything except S5 outputs (which are switched proactively by T2 via i2c interface later) should be present.
=== CD3217 checkpoints ===
If a CD3217 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 CD3217 can often cause a loop at step 10. All of the CD3217s need to be fully functional and communicate with the SMC before the CD3217 connected to the charger will request 20V
These documents are for specific boards, but will likely apply to most T2 Mac. Any net names and designators will be specific to the board it is from.
All 4 port macs require right side to be sourced from donor. Reason for that is preconfigured custom i2c address which is unlike CD3215 is hardcoded in internal bootrom. Left side uses straps to set i2c address but if you put OTP-Configured cd3217 from right side it wont work. 
inrush mosfet pair is integrated into CD3217, so after DCIN short (if it happened before Buck-Boost converter) you can expect weird charging behaviour. if your mac works from battery and from charger separately but stops taking DCIN once you plug in battery - try to replace CD3217. if all ports have same behavior, it is quite possible that customer plugged PD-passive power supply (some displays have 2-3A 5V supplies). into all ports sequenually and killed all of them. 
on M1 device might cause weird charging only if device is turned off. 
==820-01055==
==820-01598==
===T2 Power rails resistances (820-01700)===
PPVDDCPU_AWAKE 10-15 Ohm
PP0V82_SLPDDR 30-40 Ohm
PPVDDCPUSRAM_AWAKE 100-120 Ohm
PP1V1_SLPS2R 1-2 kOhm 
PP0V9_SLPDDR 40 Ohm
PP1V8_SLPS2R 4 kOhm
===820-001700 CD3217 Compatibility issues and OTP Config===
4TBT port devices have mixed OTP/Strap configured i2C address for CD3217. On CD3215 each controller got its address with debug straps around it, however logicboards with more than 2 CD3217 use OTP (firmware configured) address. There is no known method of changing this configuration however it might be possible with devboard for similar TPS Chip, so most likely, it will not be ever possible to configure chips from other devices to be used on 820-01949 or 820-001700
Left side of the laptop uses hardware (Strap) configured addresses, right side gets address from OTP config burned into CD3217. Thus, 1949/01700 cd3217 is interchangeable but you need to match right side. 
If you have a logic analyzer, you can connect to the i2c line on the debug connector to see which exact port is malfunctioning. This might be also helpful if you have a bunch of randomly sourced cd3217s and you wish to find one with the right address. 
820-01949 and 820-001700 are not interchangable because they seem to use different 5V output control. charging will work but usb connectivity wont. 
Information below might be obsolete/incorrect since it was more or less speculation based on repair experience, not actual board / datasheet analysis 
 
CD3217s from 2020/M1 boards will not work. 
Symptoms of compatibility issue: PPBUS ~12.30, all ports are switching to 19V with T2 boot/or one side will turn 19v, another stays on 5v (19v 0.05-0.1A) there will be a visible heat spot on T2 1st pin corner (inner side since T2 itself is approx 2 smaller than IC)
Device will start from charged battery, there will be no issue with usb devices but charger wont be recognized. 
Generally 001700 behaviour is very inconsistent. some boards might start with only one cd3217 present on board (should be the one connected to tbt rom of course), some will stuck in 5V 0.2A, some will stuck in 19v 0.1A(basically same power consumption). 
Probably there are multiple revisions of the board, images pending. If you can add some more info, please report your revision / cd3217 behaviour below. 
===820-001700 CD3217 revisions list===
Case 1: MacBook Pro 16" 2019 With CD3217 rev. 9AP0NVQ No power with one side of newer 12P1FXQ(took from 2020 board), Symptoms: quick T2 boot, 19V mode + hot T2 Corner on original side, 5v 0.2A on another. PPBUS 12.3V 
===820-01987===
CD3217 B12 09P09CQ
Possibly alternative revision with TI logo on chip, CD3217 B12 02P04ES 
===820-01598===
CD3217 B12 97P146Q
=== OTP Configuration on M1+ devices ===
all 2 TBT port machines without magsafe - no OTP configuration
all 3 TBT port machines (14, 16"): Magsafe (U5500 i2c: 0x3A) and HDMI side (UG400 i2c: 0x3B) are OTP-configured and need to be sourced from donor. 
Macbook Air M2 has only one OTP configured port which is Magsafe (U5500 i2c: 0x3A). this means it might be interchangable with U5500 on 3USBC+Magsafe machines
OTP Register contents:
ATC0
0000000: 81 01 00 17 18 18 AA 02 9F 66 B2 82 00 00 01 55 .........f.....U 
0000010: D9 38 00 00 00 00 00 00 00 00 .8........
ATC1
0000000: 01 00 02 17 1F 1F AA 02 9F 66 B2 82 00 00 01 55 .........f.....U 
0000010: D9 38 00 00 00 00 00 00 00 00 .8........ 
HMP1(Magsafe)
0000000: 81 01 00 17 0F 1A FE 4B 9F 66 C2 81 00 00 01 55 .......K.f.....U 
0000010: D9 38 00 00 00 00 00 00 00 00 .8........
=== 820-02862 (MacBook Air M2) ===
this board seem to have 2 strap-configured and 1 OTP configured chip for Magsafe(U5500)
CD3217B13 is not compatible with any other revisions. 
While buying chips beware of 1/3 chance of getting magsafe chip which will most likely not work on strap-configured position (UF400, UF500). There is also a high chance of getting chips from 14 and 16" macs which would have 50/50 chance of having OTP i2c address override configuration. 
Try to find supplier with chip position markings or use donor board. 
=== 820-02862 (MacBook Pro M3) ===
Like all other 14/16 inch M macs it has CD3217B13 controllers
like all other models with >2 usbc ports, 2 OTP and 2 Strap-configured. It is not clear from the schematics, which ones are strap configured, which ones are OTP. 
Most likely UF400 UF500 are strap-configured, UG400 and U5500 are also OTP. 
==Small T2 top side diode measurements==
There are more power lines than 1v1slps2r, they just somewhat got lost in the process of uploading. Maybe I'll fix that later.
Those are in case you wonder if you have a broken line between T2 and it's RAM, or have some pins torn.
==T2 types==
А2159, А2289 - Big T2 Package (PMU is also different!)
А1932, А2179, А1989, А1990, А2141, A2251 - Small T2 Package
Important note: T2 have differences in the supported amount of SSD. T2 supporting up to 512GB has 1GB RAM, T2 supporting up to 1TB and above has 2GB RAM. When replacing RAM, it is important to take into account the amount of RAM, otherwise the replaced memory of the wrong size will not work. Also, if you want to increase the size of the SSD (for example, from 512GB to 1TB on the A2141), it will not be enough to replace only the T2 RAM from 1GB to 2GB, you will need to install the T2 that can work with 2GB RAM, in other words, you need a T2 that originally came with 2GB of RAM.
Known types of RAM + APL number: 
*APL1027 with h9hknnn8kumuvr 1GB Hynix Chip.
*339S00467 - 2GB
*339S00533 - 1GB
There is also BOM table in schematics, but it listed apple part number(339Sxxxxx) does not seem to correlate (based on 5 boards). However, it lists 2 different Ram manufacturers, Hynix and Micron. 
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