Razer Blackwidow: a key not functioning

So, I was using the pc and the a key stopped working all of a sudden. I decided it may be time to give the keyboard some cleanup. After cleaning and putting it back together, I noticed that the a key was working, but only for the first 30-40 seconds after turning the computer on. After that, the key does not function and it does not trigger light effects either. I have tried reinstalling the keyboard drivers, Razer Synapse, and any other software that could interfere with the keyboard. Granted, it is fairly old, but the key works for some time, so I guess the issue should not be on the switch or the physical keyboard itself.

Any idea on what could be causing it and how to solve it?