So I already put a post on here about this F-14, which was insisting the 6116 memory (u25) was bad. I changed the output chip below the processor and it went back to working fine. Today, it has decided that once every dozen boots or so, it has a u10 error. This doesn't stop the game, which then boots and goes on working. But it's not right, and someone would like to buy this machine. There's clearly something pooping on the data or address line, and doing it very rarely. How does one determine what chip is at fault?