Here's how to perform a factory reset on the RC-505.
Caution: ALL user recordings (loops), settings, and factory demos will be lost when doing a factory reset. Be sure to back up the RC-505's contents before proceeding.
1. Turn on the RC-505.
2. Press the SYSTEM button repeatedly until "Factory Reset" appears in the display.
3. Press WRITE.
4. Turn the MEMORY/VALUE knob to select the desired range of parameters you want to reset (SYSTEM + MEMORY, SYSTEM, MEMORY).
5. Press WRITE. When "Please turn off power" appears, turn off the RC-505.