How are you trying to load the program?
1) You should be able to manually enter data (very slow)
2) You should also be able to read a paper tape (if you have a paper tape)
3) You can connect a BTR interface of some kind and download files from a PC. We offer BTR interfaces for the 5M if you need one.
To load manually
1) Clear memory: Select MEMORY mode, press the red "C" (cancel) button and ERASE button at the same time.
2) To enter data: Select EDIT mode, Run address LED to "N", key in number, then press INSERT button. Run address LED to "G", key in number, press INSERT. Run address LED to "X", key in number, press INSERT (etc. etc.) At the end of each block, press the EOB key, then INSERT Be sure to put an M02 or M30 at the end of your program, followed by an EOB.
To load a paper tape into memory, place tape on the reader and turn on the tape reader toggle switch. Select MEMORY mode, then press the READ button.
To reset to the top of the program, select EDIT mode and press RESET. To scan through the program data, press SCAN up/down keys. To change something, scan to the data you want to change, type in a new number, then press ALTER key. To erase something from the program, scan to it and press ERASE button
The operation of a BTR interface is basically the same as for reading a paper tape, only you'll have to prepare the BTR interface to send your program first. The CNC thinks it's reading a paper tape, but the BTR is simulating the tape reader inputs. In my opinion, a good BTR hookup is the best way to go with the 5M.