Is it beeping any codes? With the DESS lanyard cap off ,try pushing the "Set" button first for a few seconds...to see if it clears the "MAINT" code. Then push it 5 times to see if it has any trouble codes. If it has a code it will have to be repaired, or bought to a seadoo dealer to have the problem fixed and the code re-set. If you get a code repost and we'll tell you what it means.
Karl