1) Remove power from the unit.
2) Remove all other connectors.
3) Remove the four perimeter screws that anchor the front interface panel to the rest of the unit. Lift the front panel straight away from the unit. This will bring the circuit boards out of the unit. The battery is located on the control board, nearest the LED display.
4) Carefully remove the battery by sliding, not lifting. Be sure that the battery leaf spring has adequate tension to ensure the battery is not loose upon installation (bend down slightly).
5)Install the new battery, noting polarity. Reassemble the unit (lethal voltages present).
6) Return all connectors.
7) Apply power.
8) Establish RS-232C communications.
9a) 500 indexers: Issue the nXC command. Issue nRSE (where n is the device address of the unit). You should not get an error #30. Re-download your program. You are done.
9b) JSI controllers: Issue the nXC command. You will not be clear of the error #30 (EEPROM error) until you issue the nSV command to save all tuning etc. to non-volatile RAM. Re-download your program and issue nSV. You are done.
The replacement battery is a 3 volt lithium battery (Panasonic BR2032 or similar). These can be found at your local electronics store.