Most likely there is a memory failure the only real way to test is to reset it. How extensive is your programming? The way you start it over is to clear memory and IPL it as if it is just out of the box. You might get by like it is by using the PLU key. Does this make sense? Otherwise you must reset, then it still might have a failure in some part of the memory... Sorry to tell you this. Is the unit very old?
Let me know,
it is an old machine the PLU are not usable how do you IPL this unit might just not use those keys
yes it is old how do you IPL the unit
also might just not use those PLU keys
IPL will completely start it over, memory programming and all.
Turn it off on the right side, turn the key to the "S" position (6 oclock) with the "C" key.
Hold down the check key and while holding it turn back on the right side switch. After initialization, press the upper left key, then the upper right key, then the lower right key then the lower left key. this will check and reset the RAM. It is explained in the manual.
I will check back in the AM,