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Appendix C – System Restore and Power-Up Buttons
System Restore
The JSD-100MA has several methods of recovering from an unlikely failure. These are detailed below.
Bypass Mode
When the JSD-100MA main power switch is off and the bypass power supply is plugged in, independent bypass
circuitry creates a mono sum of the selected analog or digital input audio and routes it to the left and right
outputs. A quick way of recovering from a system failure is to turn the JSD-100MA off.
Restore Factory Firmware
If a firmware update of the main (PIC) processer is interrupted, it is possible to leave the system inoperable. To
restore the factory installed firmware, turn off the JSD-100MA, then hold down buttons 4 and 6 (Digital 16
Channel and User 2) while turning the power back on. The front panel LEDs will start flashing. They will
normally start flashing immediately, but it could take up to two minutes for them to start flashing. Release the
buttons when the LEDs start flashing. When the LEDs stop flashing, the system will restart with the original
firmware. The interrupted firmware update can then be repeated. This only restores the PIC firmware, not the
DSP firmware. Ensure the versions for each are from the same code package.
Load Configuration from SD Card
The SD card is used as a "personality module" in the JSD-100MA. Should a JSD-100MA need to be replaced, all
the saved settings from the old unit can be easily loaded in to the new unit without the use of a computer.
These settings were saved during the initial configuration using the SD Card Backup button on the GUI. To
restore the settings to a new JSD-100MA, insert the card from the old unit (behind the removable cover on the
rear panel) in the new unit. With the JSD-100MA off, hold down buttons 9 and 10 (AUX and MIC) down while
turning on the power. Continue to hold the buttons about 30 seconds until the display says "Loading from SD
card." The configuration will be loaded and copied to the internal non-volatile memory. The JSD-100MA is now
configured the same as the previous unit. Any errors (missing card, missing file, etc.) are reported on the
display.
Power-Up Buttons
The JSD-100MA checks the state of front panel buttons during power up to determine if some special action is
required. During normal operation, no front panel buttons are down during power up. The table below
describes the response of the JSD-100MA when buttons are held down during power up.
Buttons
Action
DIGITAL 16, USER 2
Restores factory installed PIC firmware and configuration. Hold buttons until front
panel LEDs start flashing. Does not restore DSP firmware.
AUX, MIC
Loads configuration from SD card and saves to external flash. This is usually used when
swapping out a JSD-100MA, as described above.
MUTE
Hold the mute button down to suspend the boot process so boot data on display can
be read. Boot process continues when button is released.
