K5 Pop-Up flash

My back-up K5 has suddenly refused to function if the on-board flash is in the raised position....I have heard of this happening before, but at 993 shutter actuations?

Has anyone any suggestions? I have tried everything I can think of - even re-installing the firmware. The camera works fine with the 360FGZ fitted and in every other way.

And I fear it is out of warranty

Regards
Roger