Has anyone opened up the turbo actuator to see what failed? Some have core charges so maybe there is an easy fix. 

Funny you post this. I am having a hell of a time with the actuator on my DPS turbonator! I found replacements from China, ordered two. One has already died. Now it goes into limp mode every time I hit about 35psi because the actuator draws too many amps. 

 

Long story short, I'm diving head first into making my own controller with a hella actuator...

The man I was helping had to turn in the old actuator and the core was voided if I opened it to see what was wrong and what was rebuilt on the new one. I suspect there is a potieometer inside for position sensing that wears out. I see John Deere uses a lot of oil pressure powered actuators on VGTs maybe better choice.

I'm going to bet its a heat issue being the turbo is buried down low on the frame and relies on coolant to cool the turbo and the electronics.

It's definitely a poor location and unnecessary. I think it was done for less noise.