Honeywell support & RMA (800) 782-4263
1) Try swapping cord from a working unit, Insert pin into pinhole (7) to eject the cord from the handheld. Try using a good cable on the bad scanner. Is there any difference?
2) On a PC, open a notepad app, try scanning UPC vendor code, does it scan?
3) Scan the setup codes on the Metrologic Voyager scanner setup sheet (see link below)
------ADDITIONAL INFORMATION--------------------------------
MS 9540 Troubleshooting Guide:
https://aidc.honeywell.com/CatalogDocuments/00-02410%20Rev%20M%201-13.pdf