First of all, I wanted to thank everyone on these forums for their posts and insights on all the various hard drive issues...and suggestions on how to diagnose the problem. Most of my google'ing and searching online brought me to several useful posts on here to help me figure out my problem. And I wanted to share my experience in the hopes that it may help someone else later on with a similar issue.

So I was in the process of building a new computer...and wanted to move my old hard drives over (which was just back-up storage)...but in the process of doing so, I quickly found out that I was no longer able to access one of the drives. A sunken feeling overcame me when I realized that this was most likely a hard drive failure since my other drives being transferred were fine. So I pulled out the drive in question for a closer look...It was a Western Digital SATA hard drive (WD6401AALS).

There was no spinning, no clicking...nothing...when I had the drive attached to power. After reading through the posts here, I learned that my next step should be to carefully take off the PCB board and have a look at the chips there. When I flipped over my hard drive PCB board, I noticed that one of the ICs, the Smooth Chip, had burnt marks on it (the IC chip on the upper right hand corner of the picture).

For my particular hard drive, I found the following:

PCB: 2060-701622-000 Rev P1
Smooth Chip: L7251 3.1

In general, what most people recommended, was to to get a new PCB board for your drive, and then do a BIOS firmware swap. However, I learned that one could not do a BIOS swap for this part. The PCB's BIOS is integrated on the Main Controller IC and so the Main Controller IC would have had to be swapped to a new PCB for the HDD to be recognized if I went that route.

I emailed and inquired at a few places online that fixed hard drives...and most were not that helpful, charged a high amount of money without any sort of guarantee, or were not clear when I said that there could not be a BIOS swap due to my particular model of hard drive.

However, the last place I emailed... http://www.onepcbsolution.com/ actually fully understood my issue...and were able to answer all my questions to my satisfaction...and were patient with everything that I wanted to know more about. They also suggested that based on the picture I had sent...that the easiest fix may be to just replace the Smooth Chip...as the damage didn't look like it may have affected the rest of the PCB Board. On top of that, they said if they were unable to replace my Smooth Chip successfully, then they would refund the full cost for the service.

So I sent in my PCB board to oncepcbsolution.com. They were also very good with communication with every step of the way. They let me know when they had received my PCB Board, when they had finished working on my board, and once again when they mailed it back out to me. I got my board back this past weekend, and then reattached it to my hard drive...I held my breath as I attached the power to the drive...and then I heard it whirl up....I then tried to access my hard drive...and was able to see all my data! Needless to say, I was happy and relieved...and then spent several hours this weekend retrieving all my data from the drive...and was thankful that onepcbsolution.com was able to help me fix and solve my hard drive problem.

With information learned from this forum, and help from oncepcbsolution.com, I was fortunate and able to get my hard drive's PCB Smooth Chip replaced and then fully recover all my data.

Anyway, just wanted to post and share this with others on here. Thanks!

Congrats to you, and OnePCBSolution! Good to hear when a business provides excellent service, and of your success.

Do you now have all of your data in on at least two different media, so if one fails or gets encrypted by ransomware you can recover it from the other? It's amazing how many people don't.

_________________
Sabo Computer Repairs & Data Recovery

Thanks! Yes, you make a very good point...

I do indeed now keep my data in two areas...especially now that drives/media are a little less cost prohibitive.

I'm sure some people realized that my drive that failed is an older drive by many years...one of the reasons for doing the new computer build was to also finally do some proper backups as well for my aging drives. And fortunately, I was still able to do that for all the hard drives that I had after getting the one above fixed by OnePCBSolution.

@wrenstar, could you tell us if either of your TVS diodes was shorted?

Catastrophic failures in Western Digital PCBs:
http://www.hddoracle.com/viewtopic.php?f=59&t=1119

_________________
A backup a day keeps DR away.

@fzabkar: When I was doing my googl'ing and researching online about the potential failures that my hard drive could have...I did see some posts mentioning the TVS diodes being potentially shorted as an issue. Though, I didn't come across the very informative post that you made and linked me to about how these are a problem on WD hard drives.

Let me dig up my digital multimeter, and when I get a chance, I'll take off the PCB board and will take a more informed look.

Sorry it took me a little while to respond. Hadn't used my digital multimeter in a long time...and it wasn't where I thought it would be...so took me a while before I could find it.

Anyway...so I took the PCB board back off my hard drive...and then tested the diodes by measuring the resistance across both the D3 and D4 devices.

In both cases, I was able to get a reading, so it looks like my TVS diodes are actually still active and not shorted in my case.

Sorry for digging up a old post.

Can you explain to me what you meant by D3 and D4 devices?

TVS Diode FAQ:

http://www.hddoracle.com/viewtopic.php?f=100&t=86

http://www.hddoracle.com/download/file.php?id=1084&mode=view (D3 and D4)

_________________
A backup a day keeps DR away.

Ahhh..ok. got it. Its the diodes.

Fzabkar, may i ask if you have any recommendations or links for a newbie lab setup at home.