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S21 FE: USB-C Controller Sending False ‘Water Detected’ Events

(Topic created on: 09-10-2025 04:43 PM)
166 Views
2bSar
First Poster
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Hello All, 

I've been a loyal Samsung-ite for near on a decade now. 

After spending about a day debugging a new device I bought yesterday, I think I’ve uncovered a recurring USB-C issue affecting the Galaxy S21 FE and possibly other models.

After ruling out the device itself, I started examining kernel logs and found evidence pointing to a fault in the MAX77705 USBC contrler and its assocated TypeC Manager (TCM) daemon.

Particularly - the issue is with the MAX77705 chipset - and the TCM (Type C Manager daemon).

The relevant log entries are shown below.

Example 1: False “WATER DETECTED” event:

 

Members_zf9SLKA_1-1760023330886.png

The kernel log from MAX77705 USB-C controller shows WATER DET=1 while VBUS is high (5 V present) and the port is simultaneously marked ATTACH=DETACH.

(My impression is that this state should be impossible under real moisture conditions, it can only occur due to a PDIC/PMIC logic fault.)

Example 2: This image shows a Immediate “DRY” transition

Members_zf9SLKA_2-1760023395361.png

As you can see - the controller reports WATER DET=1 again, but this time it then then issues a Sending DRY event notice without any physical change to the device.  

In both traces, the handshake fails in under a few milliseconds (it starts at 124.236267, and ends at 124.23635) -so the USB device never even negotiates properly.  (As you will see from the logs - both (images) events are happened quite close together (within a few seconds - essentially me un-plugging and re-plugging the device).

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It's my opinion that the MAX77705 controller is generating false moisture-detection positives, which kill power and break PD negotiation.

If anyone else has seen phantom “moisture detected” warnings or flaky USB-C accessories on Samsung phones, this might explain it.

After looking into this extensively, these findings are consistent with other user reports of false moisture warnings, suggesting a potential firmware or logic issue in the Type-C manager (TCM) stack rather than a hardware fault.

Can Samsung confirm whether this is a known issue with the MAX77705 controller or the associated firmware logic?

2 REPLIES 2
Glenntech
Samsung Members Star ★★★
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Best place is to go into the support section on the Members App and leave feedback there for development teams to see
This community is a customer to customer based forum and Samsung teams do not monitor here
keith30
SuperStar
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It's a known issue effecting a lot of users, not just with the S21 models but even with the latest models.