So while I know there is a wealth of information out there about the system 11 switch matrix, this one is new to me. I have a system 11A CPU from an F-14 Tomcat in which whenever I activate a switch, every switch from every column and row turns on with the except of the bottom two rows. A few of the switch only activate a handful of switches, but most of them trigger everything. The CPU did have very, very minor alkaline damage, but I'm thinking that it just managed to creep into the wrong spot. The board has the same issue in two different F-14s so it's definitely isolated to the board. My first thought was to change the U38 PIA but before I start replacing chips I figured I'd start a thread to see if anyone can point me in the right direction. I am good at replacing board components but bad at diagnosing where the issue is.