Rainsoft Q2 water softener

I don't know if this will help but I figured I'd put my two cents worth in.
If the triguard(clear plastic with the ball inside) is full before you start the cycle, then there is something wrong.
When you start the cycle the cams should move just enough to open the "front" valve , the water flow out should be pretty strong. If this is clogged, you probably have lots of iron in the water, or the tab isn't opening far enough. There is a little plastic disk/screen in there that could get clogged. I usually just use a center punch and break it apart from the outside ( with pressure in the tank, tap it in and allow water to spurt out to remove all the broken pieces). Be prepared with a bucket to catch the water and to shut off the pressure into the system when you do this. This clogged screen could cause the triguard to fill too slow and result in the brine tank not filling with water. The proper way of fixing this problem would be to remove the brine seat that screws into the brass valve, clean the little disk and replace the seat, be prepared with an extra seat because you'll probably break it screwing it back in. Both tabs (valves) should also be replaced. Hopefully they will pull out and you don't have to go in from the drain end to remove the bottoms of them that stayed in the brass valve when you try to pull them out.
The other problem that you may have, if the triguard is full of water before you even start a regeneration, is the poppet valve between the triguard and brass elbow is not seating, allowing the triguard to fill with water. the oring on that may need replaced, or it could be the triguard itself.
If your getting into it that far yourself, I'd replace the brine injector and orings on the piston also.