How to fix bricked Seagate hard disk (with illustrations)

This is an image based tutorial that will show step by step on how to fix bricked Seagate hard disk (model ST3500320AS). This model ST3500320AS is a 500GB hard disk but it has known busy bug or BSY error. If the hard disk is hit by this bug, its size will be detected 0 bytes by BIOS. Disclaimer: webfoobar assumes no responsibility for any data loss or permanent damage executing the following tutorial steps (use at your own risk).

Requirements:

1. 1 piece USB to UART connectivity bridge (this tutorial uses Nokia CA42 cable) with driver
2. 5 pieces wafer connector
3. 1 piece 2 x AA battery holder
4. 2 pieces AA battery
5. VOM or Multitester
6. COM port terminal software (this tutorial uses PuTTY)

 Cable Construction Steps:

• Cut the cable into two. We only need the part with USB plug. Therefore, it is logical to cut the wire with USB plug more longer. We will use the other half of the cable in identifying its pinouts in the next step.
• The cable's wire color may vary in different manufacturer so identify the pinouts of your cable using VOM. I have identified mine as (be sure to add label on each wire):
  
• Connect the wafer connector at the tip of the cable's wires (the one with USB):
  
• For improvement, add shrinkable tube:
  
• Connect the battery holder:
  

Prepare the Hard disk:

• Remove the Printed Circuit Board (PCB):
  
• Remember the position of the PCB on the hard disk and where the screws are connected:
  
• Put an insulation (something like thick paper or calling card) between the PCB and the connector of the hard disk:
  
  
• Return the PCB on the hard disk with the paper insulating the PCB and hard disk connector then reconnect the screw to temporarily hold the PCB on hard disk:
  
• Remove the hard disk jumper:
  
• Connect the customized cable to the hard disk. Here's the pinout of the hard disk:
  
• Connect the SATA power to the hard disk and wait until the motor stops:
  

Driver Installation: 

• Attach the two double A batteries. Connect the cable to the computer. The CD driver may not be needed, my Windows download it automatically:
  
• After it downloads, Windows will try to install it:
  
  
• New window will appear at the back and click that window:
  
• Click "Finish" button
  
• Message should appear at your taskbar that the driver has been installed:
  
• It is important to identify the port number of your installed USB to UART connectivity bridge. Open your "Control Panel" and double click "System":
  
• A window will popup. Click "Device Manager":
  
• Click "Modems":
  
• Double click "Nokia CA-42 USB Modem":
  
• A new window will popup. Click "Modem" tab:
  
• Take note of the port number (mine is COM7):
  

Communicating with hard disk:

Note: Make sure to follow the upper and lower case when typing on terminal.

• Open PuTTY terminal. From the "Category" column, select "Serial". Input the port number of your USB to UART connectivity bridge cable to "Serial line to connect to" field (in my case, I entered COM7), 38400 to "Speed (baud)" field, 8 to "Data bits", 1 to "Stop bits", select "None" from "Parity" dropdown menu and also "None" for "Flow control". Click "Open" button:
  

• Hit the CTRL+Z keys and it should display a prompt saying F3 T>:
  

• Type /2 and hit Enter:
  

• Type Z and hit Enter:
  

• Remove the inserted paper from the hard disk and tighten up all its screws:
  

• Type U and hit Enter:
  
  The next commands are just for checking if everything are ok (Note: this test only works for 500GB 7200.11 hard disks with firmware SD15. Type / and hit Enter:
  
  Type F712 and hit Enter:
  
  Type F,,22 and hit Enter:
  
  Type F712 and hit Enter:
  
  This is the end of the checking part. The next steps should be performed.

• Type /1 and hit Enter:
  

• Type N1 and hit Enter:
  

• Type / and hit Enter:
  
  The terminal will clear and it should display:
  

• Unplug the SATA power of the hard disk, reconnect it and wait for 20 seconds. Type m0,2,2,0,0,0,0,22 and hit Enter:
  

• Remove the SATA power and the customized cable from the hard disk. Shutdown your computer, install the hard disk to your computer and reboot. The hard disk should be working by now and be sure to update the firmware of your hard disk ASAP.

If you prefer to buy instead of building one for yourself, this tool: Complete Kit Seagate Barracuda 7200.11 Firmware Repair Fix Tool USB Power might help you.