Korg DTR-1000 - How to Start the Test Mode

DTR-1000
How to start the test mode
[DISPLAY] + [CALIB] & [POWER ON]
NOTE:
Do NOT insert any plug into the MUTE terminal while starting the test
mode.
DTR-2000
How to start the test mode
[CHROMATIC] + [DISPLAY/SOUND] & [POWER ON]
NOTE:
Do NOT insert any plug into the MUTE and INPUT SELECT terminals
while starting the test mode.