Why won't my S7 see my usb physical keyboard?

[Android Central Question]

I've been using a wireless keyboard (connects via usb dongle) with my Galaxy S7 for a while, but some time ago (more than a few months by now) my phone no longer would recognize anything was inserted. I've decided now that I care enough to bring my physical keyboard back, but to no avail. Can anybody provide any kind of clue as to what happened or how I can get my phone to see my keyboard again?

List of steps taken that have so far not worked:
Ensured system was up to date
Factory reset
Enabled developer mode and tried all usb mode settings (Power only, USB ethernet, Video Media etc)
Disabled developer mode
Force Stopped software keyboard
Cleared Data/Cache for software keyboard

The keyboard works fine with a laptop and another android phone, and keyboard used to work fine on this phone. The USB port itself works fine for charging.

 

[B. Diddy]

Welcome to Android Central! You're using an OTG adapter, right? Are you sure the adapter still works normally? Can you test it with another USB device, or try a different OTG adapter?

Please register on this forum, which will allow you to engage in discussion more easily, as well as post images. https://forums.androidcentral.com/ask-question/409154-join-android-central-community.html

 

[Rukbat]

It's possible that the pin on the USB connector (pin 4) is loose, so the phone doesn't switch to OTG mode. (It's more likely that the USB connector in the phone lost contact than that the cable went bad.)

 

[ArtosTheWarriorKing]

Apologies for the delay, the sleeps got to me.

Welcome to Android Central! You're using an OTG adapter, right? Are you sure the adapter still works normally? Can you test it with another USB device, or try a different OTG adapter?

Please register on this forum, which will allow you to engage in discussion more easily, as well as post images. https://forums.androidcentral.com/ask-question/409154-join-android-central-community.html

As suggested, I have now registered!

The OTG adapter is working fine since I tested it with another android phone with no issues.

It's possible that the pin on the USB connector (pin 4) is loose, so the phone doesn't switch to OTG mode. (It's more likely that the USB connector in the phone lost contact than that the cable went bad.)

That sounds possible, is there any way I could test this without taking the phone apart? Or, more importantly, is there any fix that doesn't involve getting inside the device? I'm a hobbyist with electronics so my first thought would be to resolder the usb adapter joint but I'm not entirely confident I can take apart the glass screen without cracking it. I will if I have no alternative though.