JRC JMR-92 Series Field Service Manual page 762

Update of Firmware
5.6
When you want to use a USB flash memory to read or write a file, make sure in
advance that the USB flash memory is not affected by a computer virus. If the
display unit is infected with a virus, other equipment will also be infected, with the
result that a trouble will occur.
Before removing the USB flash memory, check for the access lamp of the USB
flash memory and make sure that it is not being accessed.
If you remove the USB flash memory when it is accessed, data may be destroyed
and a trouble may occur.
Do not turn off the power during firmware updating.
Otherwise, a function may fail, and an accident may occur.
Do not do the firmware updating operation of data while sailing.
The radar application should be ended to begin the data backup. It becomes
impossible to observe using radar and this may lead to accidents.
Whenever you try to CCU or TOPU firmware updating, always make sure that
the backup power is fed to the PSU of the Display Unit. Unexpected shutdown
during updating may cause a system malfunction.
This section describes the procedures for CCU, TOPU, and SLC/ALC firmware updating.
5-19 Section 5 Software Update