Now I believe my problem is much worse. I was originally getting the Netplex link is down error. I changed the battery on the MPU board and got the machine to boot and work. After turning it off and back on, the dreaded Netplex link is down error is back. Cannot get it to go away by a key reset or anything. Guessing the main MPU board is bad and cannot find a 75512702 board anywhere online to replace it. This machine is driving me nuts. Any suggestions? I went through the whole machine and cannot find any loose connections anywhere.