4020 will not CS today

I've only had this mill for a couple weeks and want to thank those of you who did help me initially get it running.
This is a 1997 4020HT , Everything was fine last night when I shut it down.
This afternoon after booting the control it will not cold start.
All axis' will jog to the markers and after keying in "CS" the screen goes blank for a couple seconds and will
prompt for returning to the last fixture position. Keying in yes or no will cause the screen to again go blank.
After the video recovers a few seconds later the prompt has reverted back to "jog to cold start" .
Should you try to jog the axis' at this point they will rapidly jump around a 1/4" .
I caught a glimpse of an onscreen message on one occasion that had something to do with memory.
It was so quick I couldnt see all of it.
There however isnt any error codes or messages on pg. 47 of the menu.
Does anybody have any ideas?
Thanks again

Replace the battery back-up......First use the setp command and write down all values..... then use the BL command and write this down.......If its an AC servo motor machine look at the SV command and write those values down....... The battery is really easy to replace but on most machines it is soldered on. Look up the memory clear procedure, it is in the manual available at Motion Machine Technologies LLC. | TEST zero the memory, replace the battery, replace the parameters and you should be good to go.

Motion Machine Technologies LLC. This is the one your looking for. Motionman has some good advice. I don't want to come across as nancy know it all but don't worry about the parameters there are only 30 of them or so. Very few to enter and also don't worry its multiple choice...lol.

Motionman have you worked on any 104D machines? Have you ever gotten one successfully going? I see very few left on the market and with a little tweaking...hmm.

Havent had any issues since the previous noted day.Anybody ever have humidity issues with these machines?

Yes and virtually every fadal that shipped from the factory had bags of dessicant in the control cabinets. Get some in there.