I was taught to heat press hash when I was in Istanbul. Ganja Smoker, your temps are way to high! The kief to be pressed is wrapped in wet newspaper for a purpose - it limits the temperature of the kief to 100C. While the newspaper is wet, the hash will not get any hotter. The temp you are using is close to the vaporisation level for THC and you will be damaging your hash and diminishing the flavour and aromas. Terpenes boil off quickly if you are not careful, leaving your hash with a bland odour. Try it again but only have your oven temp set at 250F. Make sure the newspaper does not totally dry out. I think that you will get a much better result next time.