<VV> No boost?

[Grant]

I am trying to advise a customer on what to do next. I rebuilt a turbo that was not boosting. It was not awful, but I replaced the carbon seal, bearing and bushing and mic-ed to stock. Only had to install a shim under the bearing, but still no boost. Customer has checked the exhaust for leaks, the linkage for wear, timing, and compression at around 120. Carb has recently been rebuilt and getting fuel and there is no smoking. Rotating unit goes about a turn or so when flicked with a finger and is not binding. Car runs fine otherwise, just not boosting. Hoping someone has an idea on what to look at next?
Thanks,
Grant