Sony PCG-7Y1L

i had issues with the operating system so I did a format of he hard drive and then it wouldnt read the cd to reinstall operation system. so put in a digosnostic CD and it had 25 steps you could perform. so from there i formatted again and made sure the partition was set, then i did a cmos wipe. said wait 30 seconds then restart computer. Well, tried restarting it and nothing happens, i get a blank screen - doesnt even get the Vaio screen. tried loading cd's and nothing happens, it wont book up from a cd or anything. Can someone please help!