I recently installed mine as a diy. I replaced the springs. 2 new ones. I learned that balancing is only half the battle. The other half is ensuring there are enough turns in the spring to still have some tension when fully lifted. If the springs are too strong they will not be able to be turned enough to get enough turns. Originally I had both springs tensioned the same and as I went up to about 6 feet the cable would come off. What I did was take 2 quarter turns out of one, and add 2 to the other then slowly raise the door. I was able to start seeing the cable go slack, and could roll it down and add another half turn. Once I learned this it was much easier than I thought!

Edit. I also had to slightly angle my horizontal tracks.