Pnc 1100A error message

My Roland pnc 1100A has always worked without flaw until recently.

On startup, The Carriage does not move as usual and "PNC 1100" is on the display as normal for about 2 seconds and then the display reads "OPERATING ERROR CAN"T FIND LIMIT" and the menu and enter button do nothing....

The carriage moves freely by hand and I have cleaned the limit sensor (optic part) with electronic cleaner.

If I move the carriage so that the optic sensor is lined up with the metal tab (optic field is broken) The error message does not display but it does not do its normal startup (carriage moving and settling to the start position and the menu button is not operational to set up as "sheet or roll".....

Does anyone have any thoughts? I am in Central America so a pack and ship to a service center is not easy or cost effective for me.

Many, many thanks for any help!

Jay
702.953.4700 (US#)