that works,
the book I have is for the bc30s2, but it should be close, and if I am mistaken, I am sure someone will correct me.

Display = "E" (Flashing) Lift truck will not
operate, Possible cause, seat switch open.

Display = "E" (Not Flashing) No lift truck
operation.Possible cause, static return to off.

Display = "1, 2,... F" (Continuously Changing)
Low battery, lift lockout will occur. Lift truck battery
is at 80% discharge level and lift lockout is
approaching. Possible cause, low battery.

The low battery should only prevent lift, not all functions including back up alarm.
This complete of a shutdown indicates it is most likely a fuse problem, to me.

Not to sound dumber than usual, but are you sure it is a "6" and not a lower case "d"? I have made that mistake, and the lower case "d" would mean the "drs" switch is in "d" with the fuses in place.