Anyone familiar with building midi controllers?

[adding_to_the_noise]

I recently started a project that I thought was going to be fairly easy, but I'm running into problems that I don't know how to decipher. I found an old keyboard in my closet and decided to convert it to a midi controller. Using the continuity setting on my trusty meter, I figured out the layout of the keyboard matrix. I'm pretty familiar with the theory on how to scan the matrix to detect which keys are scanned, but i'm getting screwy results. I have tried testing it many times, and using the schematic i figured out which keys to use to test, but the right keys never seem to be triggering. I have noticed once or twice i will hit a key that will pull the signal to ground or reverse polarity, but it is never the right key according to the matrix. Has anyone attempted this before or is familiar with trying this that can help?