JVC KD-AVX1 Service Manual page 36

4.6.8 Update method of firm ware
Power on.
Insert the disc which a farm was written in at.
Screen indication
VERSION UP DISC
PROGRAM WRITING MODE
CURRENT VERSION 0735
NEW VERSION 0795
READING...
If "PLEASE EJECT" was displayed
after the writing end, take out a disc.
Close a panel and confirm a version.
Power off.
1-36 (No.MA165)
Current version
Version to write in
Confirmation method of a version
Keep this state more than 2 seconds while continuing pressing
the [DISP] button, [VOLUME+] button and [EJECT] button
sequentially to enter this set in service mode 3.
Select the service mode and press the [OK] button.
Select the version and press the [OK] button.
JD4
It is a version written in.