Could the packing on both lift cylinder pistons be blown? What other things could it be? Float valve stuck open?
Can't find copy of operator's manual, but, there is a "dead engine boom lowering valve" on there somewhere. Could you have it accidentally activated?
Make sure the lever marked with the arrow is moved as far as it will go in the direction towards the joystick.
nige thanks. that was the issue. have an issue with the 259b3 as well - parked it for a week and now it wont start, beeps constantly and flashes lights in the dash