Mitsubishi Electric MELSEC Q Series User Manual page 222

11 TROUBLESHOOTING
Error Error
code detail
Sum check error of parameter stored in
the FLASH ROM. (The system's power
800 1
supply was turned OFF in FLASH ROM
write.)
Data cannot be written to the FLASH
801 1
ROM.
System errors (1 to 999) (continued)
Error
At power supply ON
At FALSH ROM write/
parameter initialization
function use after the
system error
occurrence
Operation status at
Error check
error occurrence
Unit READY does not
turn ON.
(Note)
FALSH ROM write/
parameter initialization
function can be used.
FALSH ROM write/
parameter initialization
cannot be executed.
11 - 5
MELSEC-Q
Remedy
Return to the parameters at
factory default using the
parameter initialization function.
Replace the QH74MH.