USB Devices not working on Catalina after water spilled over keyboard

Question

The other day I spilled water on my MBP 2017 keyboard. I let it dry for 48 hours before turning it on again. And it ran fine.

Ever since that spill, however, I have not been able to use my USB wired mouse on my macbook. Power still runs through it (Charges my iPhone, Powers USB LED) but it does not detect any devices anymore like my USB Wired Mouse. When I check System Report, it doesn't state any devices plugged in.

• I tested the mouse on my PC and it works fine.

• I've tried several different USB C to A adapters. Same result.

• I tried restarting several times.

Is this a software issue or perhaps it's due to water damage?

EDIT: It still detects my USB Flash Drive, how is this possible?

SMC doesn't seem to reset when I try to..? Is it normal to immediately fast-boot after performing an SMC reset?

Answer 1

Is this a software issue or perhaps it's due to water damage?

It’s water damage.

The USB port (this is a generalized description) has several pins, but it’s basically two categories - data pins and power pins. Your USB supplies 5V and up to 500mA. If USB-C, it can be up to 20V. This comes from the power rails managed by the SMC. The data pins go to the USB controller chip. Your symptoms point to the fact that the USB controller took damage.

SMC doesn't seem to reset when I try to..? Is it normal to immediately fast-boot after performing an SMC reset?

An SMC reset isn’t going to fix the problem because the power portion of all this is working. The bottom line is that you have physical damage and “a simple water spill isn’t so simple.” You need to take it in for service.