Join Date: Jan 2017
Location: Southern Ontario
I am having EXACTLY the same issue with a Kubota plow that has a hydra power unit with electric controls - the same as most truck mounted plows. I searched out this forum for answers and found your post.
I have triple checked ALL circuits and IMHO it is not your controller but a bad C valve. IOW, one valve is defective and is not opening to allow the hydra fluid to enter the cylinder.
I'm now trying to sort out which one on mine goes to which cylinder, as it's all on one block with no ID. Next is finding a replacement that will fit.
FWIW, I'm attaching a photo of the block with 3 valves. On mine, it's power up, gravity down, power left angle, power right angle.
Hope that helps somewhat.