Diplomat ACA6421 stopped working 2 days after connection?

I bought a Diplomat ACA6421 from MFI as part ofa display kitchen when they went bust.
Now fitted the kitchen( sat for several months in store).
Unit worked at first , but has now died.
No problem with mains supply.
If I flick the mains switch on and off I get a flicker from the internal light unit, but nothing else.
Frustrating as unit fired up first time , but only lasted 2 days.
Assume out of warranty as MFI mo more and unit purchased as part of package .

Anybody help??