I have tried (as suggested in previous posts) reseating all component especially the left hand side riser all with not success and the fault still exists.

Hi, recently i forgot my admin password to recover that i changed all passwords in set up-security-boot password, admin password, system password, hdd password. Now it is showing error for HDD password..!!! Plz help me out for this problem. Model is Dell Inspiron N5010

When cool laptop boots up the cooling fun does not work and it is ok. But after about 30-50 minutes of usage (on 0% of processor utilization on average) it turns on cooler and speeds to ~2600RPM. The problem is that it never slows down.