Absolutely no boost (or power) driving to work this morning.
I thought I must've blown a hose on the intercooler plumbing somewhere, but when I checked it was all in place.

I've noticed a bit of a buzz eminating from near the turbo over the past few weeks which I thought may have been the wastegate vibrating.

A change in the exhaust note too.... Louder, almost like there's a hole in the exhaust (which there definitely isn't).

I'm thinking that the turbo's shat itself.

Just can't understand it because I thought there'd be smoke if the turbo went.

I know I'm clutching at straws, but is it possible the wastegate's stuck open or something?

sounds like a jammed wastegate to me, all your exhaust gasses are bypassing your turbo. Check the cheap easy options first and hope for the best.

also possible the manifold to turbo flange gasket is leaking - explains your "hole in the exhaust" noise and lack of boost.

Your turbo has to be hanging off by a big gap for it to be making no boost at all. If it's still fairly flush with the manifold when you blow the turbo-manifold gasket the car still drives almost like normal with only a slight power loss.

What sort of turbo are you using? It sounds like the symptoms of a ceramic wheel turbo that has shat it's exhaust wheel.

pull the inlet off and have a feel of the shaft. That might be the best indication of if you've blown it. I blew a turbo once and the shaft was really stiff to turn.

Running a T28 off a S15 SR20, so that discounts the ceramic wheel theory.

If the bearing's have gone, I suppose it'd jam the wheel.... No boost, but still allow the exhaust gases to escape.

Will pull the inlet off tonight & have a look.
Still praying for a jammed wastegate....

I'll check the flange gasket too, but methinks I'd still have some boost if the gasket had blown out.

it is common to blow the turbo to manifold gasket, done it a few time myself... see if you can wiggle the turbo on the manifold, if it moves even a tiny bit then theres an issue.

if the wast gate is jamed it has to be jamed open if it were jamed shut you would have "heaps" of boost

i also think waste gate jammed open, take ya dump pipe off and take a look...
it happened to a et pulsar i had once.. cos i used a rusty really really crap turbo... did'nt last long

just to make things easyer before pulling anything apart i would just find the vacume line that runs the the wastgate actuator,pull it off, get sum tubing push it on and see if u can get the actuator to move by blowing or sucking on it.

you will have to blow pretty dam hard i think... just take it off and see if you start making any boost at all, but be carefull cos if you do make boost there will be lots of it...

Edit: also if the waste gate has broken off inside the dump pipe the actuator may come across to be working when you suck and blow.. somthing to keep in mind i spose...