Roland VOCAL ECHO RVE-800 Service Notes page 13

3.
Input a sound signal from any input jack.
4.
Switch the foot switch on and off, and check the following.
Foot switch EFFECT LED (red) Sound that is output
OFF Comes on
ON Does not come on
ECHO effect
(On and off check of the foot switch can also be performed by inserting
and pulling out a standard plug with signal and ground short-circuited).
Only the sound that is input
Sound that was input and sound with
RVE-800
13