Hi Good people, I have a sit on Husqvarna CTH151, had it serviced about a year ago, cant work out what's wrong, see attached picture. Basically its not cutting right, I've had it up on ramps and the blades look ok, removed some debris, took the collector off the back and tried it, seems like when you drop the deck to cut, in some circumstances the blades don't run right, they are just not cutting and there is no exit from the back, I tried different heights (Of the cutting deck) but no luck. Its a difficult one as its like 1/2 working, But its not right! Any suggestions would be appreciated?