2040 3 point lift

[Dale2]

I have a 2040 non power shift or shuttle shift tractor that the 3 point lift feels like it is locked at the raised position. I have removed the top of the lift from the tractor and the lift arms will still not go to the down position. All the levers move and seem to be in the right spot. Does anyone know what I should be looking for. Nothing appears to be broken or bent.
Thanks
Dale2

 

[Tx Jim]

Sounds as if rate of drop screw has been accidently closed.

 

[used red MN]

Sounds as if rate of drop screw has been accidently closed.

Number 1 in pic.

 

[JIM MN]

Did you trouble-shoot with a service manual? Your 3-point arms lowering oil is trapped. Nothing appears to be broken or bent? I agree with TX Jim.