MPC 1000 "Mode" button Issue

Yeah thats ugly. First of all, make sure there's no solder bridging any of the traces together. The only place you want solder in is the contact points. Also, make sure your soldering iron is low heat (15 watts), any more and you can do some real damage. For that one contact point, it looks burned but I can't tell to what extent from the picture. If you have an electrical meter, you can do a continuity test by placing one lead on the burned contact point and another lead on a trace that is connected to it. If the meter rings, you have continuity and that contact point should still be good.

you won't have to get a new pcb. just get those tact switches off ebay and pop em in. they'll look just like the ones you're replacing and you'll know what to do. props for being ballsy and doing the job yourself.