I have a 2006 boat with 4.3L engine and an Alpha 1 lower/drive unit. The problem is, the drive unit is stuck in the up position. When trying to lower the unit by pressing the down arrow on the control you can see the hydrolic lines flex but the drive unit will not go down. The boat has been out of the water for 6-7 months. Everything worked fine during the last use. I'm open to all suggestions to remedy this problem.