another troubeshooting you can do is to check the hdd for any errors. if you can get to a working computer, check out the manufacturer's website of your hdd any download the diagnostics utility of you dont have one.
then bootup with the diagnostics utility with you hdd hook into your computer and test it for any errors. good luck!!! also try a simple solution such as replacing the hdd cable.
then bootup with the diagnostics utility with you hdd hook into your computer and test it for any errors. good luck!!! also try a simple solution such as replacing the hdd cable.