Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

[kuba2102]

Hi. Having this M1 after liquid it has only 5V on USB ports, but oddly it can be powered on from the battery source only without a jumper S5191.

Liquid affected IC's:
UF400, UF500
UF725, UF720, UF710
UF260
UP800, UP900, QD530, UC710, UD560

UF400 VOLTAGES:
PPHV_INT0_AONSW.............5.15V
PPVBUS_USBC0...................5.16V
PP1V5_UPC0_LDO_CORE .....1. 59 V
UPC0_SS............................0V
USBC0_3V3LDO_EN.............1.8V
PP1V8_S2 ...........(PIN L20)..1.8V
PP3V3_UPC0_LDO (PIN C22) 1.8V
PP1V25_S2.........................1.22V
PP3V3_S2_UPC....................3.31V
PPVBUS_USBC0...................5.16V
PPHV_INT0_AONSW.............5.15V
PP5V_S2.............................5.19V

On the schematics it says PP3V3_UPC0_LDO but openboardview says PP1V8_S2, So I assume that the schematic isn't correct? Pins PP1V8_S2 (PIN L20) PP3V3_UPC0_LDO (PIN C22) go to the same component pin, another words are bridged.

UF500 VOLTAGES:
PPHV_INT1_AONSW...............5.15V
PPVBUS_USBC1.....................5.16V
PP1V5_UPC1_LDO_CORE .......1.58V
UPC1_SS..............................0V
USBC1_3V3LDO_EN (PIN L18) 1.8V
PP1V8_S2 ..............(PIN L20).1.8V
PP3V3_UPC1_LDO..................3.3V
PP1V25_S2...........................1.22V
PP3V3_S2_UPC......................3.31V
PPVBUS_USBC1.....................5.16V
PPHV_INT1_AONSW...............5.15V
PP5V_S2...............................5.19V

On the schematics it says PP1V8_S2 but openboardview says USBC1_3V3LDO_EN, so I assume that the schematic isn't correct? Pins USBC1_3V3LDO_EN (PIN L18) PP1V8_S2 (PIN L20) go to the same component pin, another words are bridged. I'm not sure if those schematics can be trusted. I have been going through test point on the board that clearly have some voltage in it, yet schematic claims that is NC.

Conclusion. I couldn't find any abnormalities on the board, I have identical working board to compare and the voltages measured are identical. ;/;/

[mon2]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

UF400 VOLTAGES:
PPHV_INT0_AONSW.............5.15V
PPVBUS_USBC0...................5.16V
PP1V5_UPC0_LDO_CORE .....1. 59 V
UPC0_SS............................0V
USBC0_3V3LDO_EN.............1.8V
PP1V8_S2 ...........(PIN L20)..1.8V
PP3V3_UPC0_LDO (PIN C22) 1.8V
PP1V25_S2.........................1.22V
PP3V3_S2_UPC....................3.31V
PPVBUS_USBC0...................5.16V
PPHV_INT0_AONSW.............5.15V
PP5V_S2.............................5.19V

Is this a correct measurement ?

[kuba2102]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

I think that my post might have been either misunderstood or hasn't been read fully. Yes it's correct. Same voltage when measured a working M1 motherboard.

On the schematics it says PP3V3_UPC0_LDO but openboardview says PP1V8_S2,

[kuba2102]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

Got it. Manage to find a short, the guilty parts name was UP900 keyboard backlight pwm. I thought I'll be able to source out the part from the old 2019 MacBook Pro but it's got different components. Does anyone know where to get it or some sort of substitution to it? Kind thank you

P.S. Never fully trust the schematics, they are cheeky bastards

[mon2]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

Sure:

https://www.findchips.com/search/SN74AXC1T45DRL

Be sure to watch the suffix which defines the package of this device = SOT-5X3.

DK:

https://www.digikey.com/en/products/detail/SN74AXC1T45DRLR/296-47599-6-ND/8111087?utm_source=findchips&utm_medium=aggregator&WT.z_cid=ref_findchips_standard&utm_campaign={0}

[kuba2102]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

Thank you for that. Can I just ask tak the device package in this case SOT-5X3 is just a part dimension or specs as well? Cheers

[mon2]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

It is only a package definition. Required to match the pcb landing pattern.

[kuba2102]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

Hello again. I replaced the part it solved the problem for a wee while then again I only get 5V. According to Louis Rossmann if you only get 5V and your CD3217 is not boot looping it means it's a bad one. In my case none of the ICs are boot looping. I have replaced the CD3217 from macbook pro 2019 (hopefully these are interchangeable) and again I get no boot loop on that new IC, which makes me think in it's not only that both CD3217 must have communication between themselves to initialise 20V, but there must be some extra communication going on either to UF000/UF100 or the SOC itself. The thing is very occasionally I get 20V and battery charging, also my battery still has charge in it and If I leave the battery connected and plug charger in it boots with 5V only but not charging, once system is loaded after unplugging and replugging the charger 20V 0A appears. This is baffling..

[cnunez]

Re: Macbook pro M1 a2338 820-02020 water damage only 5V but powers on from battery

Good day guys ,I got the same issue CD3217 5V bootloops after 6sec. ( 20V) Not present )
i believe CD3217 is corrupted ) or may be both chips are failing.ill try to make a video if i get a programming box to fix the issues soon.