There may be a malfunction (except directly after the BEAT EFFECT's [DELAY, ECHO, SPIRAL, REVERB, TRANS, FILTER, FLANGER, PHASER, ROBOT, MELODIC, SLIP ROLL, ROLL, REV ROLL, SND/RTN (MIDI LFO)] selector switch is set to the SND/RTN (MIDI LFO) position, in which case the indicator flashes for about 2 seconds).
Read "Warranty and After-sales Service", then contact your store of purchase.