Believe me, I went through hell when I desoldered my Octagon's switches because they had short-legged SIP sockets that were very difficult to desolder even with ample solder and a desoldering iron. ChipQuik was the best way to remove those kinds of SIP sockets for me. Especially since the melt temp is lower than the housing's melting point.
Anyway, I went through having to fix SMD RGB LEDs that went out, replacing diodes, and repairing pads and traces. It was hell, but I was determined not to let my baby, my first korean custom, be a $400 brick. I kept at it and ended up fixing it perfectly.
I can say I'm 90% sure I can fix your PCB if you'd trust me to work on it. If not, that's alright! I know I'm not very well known around here and my reputation doesn't precede me, haha. The PCBs are dual-layered as far as I know and even if a through hole or pad is completely ripped, I have ways of restoring the connection. That's what it seems it might be in your case.
Here ya go:
http://i.imgur.com/1IrcwUZ.jpg
The 7 key is to the left of the screw hole
edit: also tried a few different switches in the slot, so it shouldn't be an issue with teh switch itself
plug it in, take a pair of tweezers, and try to jump the connection, like you would for anything else. The only thing I could guess is that the switch is bad.
tried to jump it with a spare wire, every key registers except the 7  
whose my best bet in the USA to possibly fix it?  
I do soldering services, but not repairs  what do you think you might have done? is there something wrong with the diode?
 what do you think you might have done? is there something wrong with the diode?
no idea   its probably something I did when desoldering the old switches. The only thing I can think of is that I ripped out the internal part of the pad by not removing all of the solder
 its probably something I did when desoldering the old switches. The only thing I can think of is that I ripped out the internal part of the pad by not removing all of the solder