Garden drain blocked

Mr_da

Hi I’ve read a lot of different posts on blocked drains and tried just about all I can before making the dreaded phone call and getting a professional in. I just want to see if there maybe a trick I’ve missed.
The drain which is blocked is the garden drain off the drive and gutter pipe. I’ve put vinegar and baking soda down, jays fluid, caustic soda. I’ve used a plunger, and tried drainage rods but they won’t go around the bend. Also boiling water and pressure washer.
I’ve managed to get quite a bit of gunk and wet weeds out, but it still won’t drain properly, well hardly at all really. Any input thanks in advance