Hi,
Thanks for reaching out to us. Let's try few other troubleshooting steps:
1. Check in BIOS if the hard drive is detected. Load BIOS defaults. (Press F2 on Dell logo screen to enter BIOS setup)
2. Re-seat the hard drive to ensure the hard drive cable is properly secured.
3. Run hardware diagnostics and make a note of the complete error message/codes.
May I know the results of the hardware diagnostics? Were you able to successfully boot in Safe mode? The lock LEDs are diagnostic indicators and I will need the system model number to check what it means when 9 is lit.