2003 Peugeot 307 SW HDi 110

My recently acquired 307 lacks power. Everything happens in the first
half inch or so of accelerator pedal movement. Pressing it beyond that
has little effect.

The local garage has just changed the timing belt at 95000 miles. I
had them check for fault codes but they found nothing wrong. They
reckon that the turbo isn't spinning and advised me to take it to a
Peugeot dealer, something I'm reluctant to do, given the way they
charge!

I've checked the air flow sensor which is working normally. Are there
any other sensors I should look at before biting the bullet? If so can
anyone suggest where I can find the normal sensor readings?

Thanks in advance

Richard