You will need to look at the silk screen on the PCB or for a sticker affixed to it that says Revision information. The Firmware version is sometimes easy to identify with a label on the top of the ROM chip, other times you need to use a tool to call the S.M.A.R.T data to see this info polled from the ROM chip.
If your running Windows 8 or newer you can use this:
http://www.windowsnetworking.com/kbase/WindowsTips/WindowsServer2012/AdminTips/Admin/find-disk-firmware-versions-using-powershell.htmlBUT you would need to have the system running off of a healthy drive to run this and then connect to the troubled drive as a slave. Also not sure if a drive with clunk of death will work for this or not since it wont be mounted by the OS.
From the link above:
Question: You need to check firmware versions on the disks of your Windows Server 2012 and Windows 8 computers (and above). How can you do this?
Answer: Use the Get-Disk function that is available beginning with Windows 8 and Windows Server 2012. Select the friendly name and the firmware version. This command appears here:
get-disk | select friendlyname, firmwareversion
By the way trying to find an exact firmware version if even the same rev PCB, you might be looking for a needle in hay stack as for the drive manufacturers have been known to change the firmware on the fly with production so one model of hard drive might have quite a number of different firmware versions. If your lucky you find 2 drives that were manufactured about the same time and hopefully they are from the same firmware release.
I have heard about people doing this with mixed results of failure and success. The data recovery centers sometimes do this by locating a matching PCB for the drive and pairing the troubled drive with a new drive controller PCB to get the data recovered.
