I have a IBM 520 with 5.3 loaded on it. I am having a problem with the console monitor not coming up to a login. The console monitor is either a ibm3151 or a wyse 150 serial terminal. The CPU boots up but nothing will come up on the console. Does not happen on install, but rather a week or month later. All other terminals will work. Any suggestions as to where I can go to solve this problem. Not happening in all shops but is becoming more and more a problem.