Help with an older skyjack 3220 won't go down

[Bubbo89]

I have an older skyjack lift and recently we replaced the control box with a new one. That cured a lot of problems with the lift but now if you go all the way up and Mac it out it will not lower you. Only way if someone is on the ground and opens the dump valve can you get down any help would be great thank you

 

[gray21]

First thing is, skyjack has all their manuals online, go to the site and pop in model or s/n, check your power at the lowering solenoid at the block on the base, make sure its got the 24v or close to, make sure the solenoid is working as well, I usually just pull them off and make sure when energized they have a magnetic field inside the coil. Do that on the lowering valve on the bottom of the cylinder as well. These units only open that valve and uses the weight of the platform and pressure inside to lower, single action cylinder, fairly simple system, should be electrical since when you manually lower it, its working fine.