Originally posted by graeme83 It was sold as used to work fine but not tried recently
First thing that comes to mind to me is open up the battery compartment and make sure it hasn't leaked everywhere or developed corrosion. If all is good there, change the battery for a fresh one. I recently inherited a P3 which wouldn't play nice until the cap of the battery compartment got a good scrubbing. There was no rust as such and the battery looked intact, but a silvery metallic deposit had built up and was interfering with the current.
Once you have power, the shutter will fire. Check in the broadest sense that the meter is working - point it at areas of varying brightness and check that the shutter speed indicator (telling you what it thinks you should dial in) is responding appropriately, likewise to changes in the aperture for a given level of exposure, and that the indicator changes when you alter the shutter speed manually. If one of your new lenses is a Pentax A lens or newer, check to see that the camera responds in program mode. If it isn't, grab the nearest F, FA or DA lens and slap that on. Yes, the DA may vignette, but the point is that the camera should recognise it as an A lens and respond in an appropriate way. After that, it's over to the experts.