Gestetner B147 Service Manual page 437

FIRMWARE UPDATE
Error during Verification
If anything abnormal is detected during verification, an error message is
displayed:
PCcard -> ROM
Verify Error
Printer Card No.: 1/1
B146S926.WMF
The second line tells you the name of the module where the error was detected.
If an error occurs during verification, switch the printer off and download the
firmware from the SD card again.
SM 5-149 B147/B149/B190