have a sony vaio desktop model pcg-252L all i get is a white screen can not get to bios or anything totally white can not find any information on this issue other than laptop have checked connections all ok at this point "note" hard drive seems to be working very hard but still white screen have disconnect memory leaving one in and still same issue then change out memory for another and same issue dont know where to be lookign for this any help is greatly appreciated at this point