Sony Vaio not able to boot properly

I have a sony vaio for less than a year. I checked it for normal disk repairs. Since than it shows the screen i.e. screen with VAIO written and dots moving round and round. Then it converts into a black screen and then it never continues.. If i restart it then also the same problem prevails. Please any1 help me... please its brand new worth more than 150 k.. my dad does not know about this and this laptop is his gift. so please any1 help me..