CM Storm QuickFire Stealth issue

[Nitto_]

I'm not sure if this is allowed or not---
I just recent purchased my first 10-keyless board yesterday and it was used. It was a CM Storm QuickFire Stealth with Cherry MX Browns. I picked it up for 10 dollars because the kid said it was, "untested". I gave him the benefit of the doubt and I took it anyways. I proceeded to take it home to test it out and low-and-behold, the backspace doesn't work. Every other key does and it's something I wanted to investigate. I took a picture of the board and I'm not sure what exactly to make of it. The soldering point don't look corroded however, the connector on the board appears to have a little bit of something on it. The board looks as if someone might've spilled a little something on it. I just wanted to post a picture to see if anyone had any insight of what I could do, next. Any help is appreciated.

[CM Storm PCB](https://imgur.com/gallery/Z69XY)

[PCB](https://imgur.com/gallery/bkVSP)

[Nitto_]

Edit:

I am sorry if this is in the wrong place entirely. I did notice that there have been "Left ALT Fixes" by scraping away the green portion to expose the metal of the trace and then using a jumper to fix it all - However, I did notice that my Traces are not necessarily as skinny as the ones in the pictures. I feel as if there may be something else that I will be needing to do. Any help or advice is truly appreciated. Thank you all!

[Tactile]

With the keyboard plugged in short the backspace switch contacts with a pair of tweezers or a bent paperclip. This will tell you if it's the switch or something on the PCB. This is the first place to start.

[Tactile]

BTW, if you don't have a keyboard test program you can find one here.