PROBLEM : iMac 27inch i5 would slowly ramp up its HD fan just by simply using Safari app. and browsing net to the level that sound of air and fan becomes uncomfortable to deal with. On phone with Apple support i followed following troubleshooting steps make new user account did NOT help reset PRAM did NOT help reset SMC did NOT help repair HD from DVD did NOT help reinstall osX from DVD did NOT help Then I went and checked vent stats, resulted following reading ODD from 930 up to 1200 rpm HDD from 2250 up to 4202 rpm !!!!!!!!!!!!!! CPU from 939 up to 1000 rpm ,while browsing with app. Safari. Finally I rebooted iMac with pressed D to get into AHT diagnostic Apple Hardware Test came back with following Hardware error code : 4SNS/1/40000000 : THOD - 9.000 What to do? I contacted authorised Apple reseller that this iMac is from and they declined to pick up my machine and replace it even though its 12 hours since i signed UPS delivery slip at my house, while Apple support suggests to take machine to nearest service and get it repaired under warranty. I would really prefer to have it completely replaced as opposed to being serviced 2nd day in my ownership. I got frustrated and whole experience that should be pleasurable went into bitter tears ! Should I press sales point on that mater and get it replaced or swallow this pill and just get it repaired?