chemshawn wrote:
I had a WD Caviar Green drive stop working recently and determined that the issue was likely with a failed PCB on the drive. By "stop" I mean that the unit simply stopped working as though it wasn't getting any power ... and even the LED lights on the enclosure wouldn't come on when the unit was powered up. There were no symptoms whatsoever prior to the failure on the drive.
The PCB may have failed because of something else. How was it determined ?

chemshawn wrote:
At any rate, I attempted to get a replacement PCB from one of the companies that offers such things. However, with this particular drive a firmware transfer was required. Unfortunately, the company ran into issues with the firmware transfer (the cpu chip with the firmware from the original drive was reported to be bad) and they were not able to create a new, working PCB.
No wonder

chemshawn wrote:
Results of PCB Swap:
Based on the initial results of a straight PCB swap (no modifications to the PCB or any sort of firmware transfer) I am hopeful that I am close to getting the failed, patient drive up and running long enough to retrieve the data. Once I swapped the PCB and tried to start up the failed, patient drive here is was I observed. When the enclosure is powered on, the unit issues a short "beep" followed by the distinct sound of the drive spinning up. The spin up takes a few seconds. Once the spin achieves a steady state, the drive issues the faint sound of what seems to be the drive heads moving around inside the drive. This sound continues for maybe 4-6 seconds before it stops. After the faint sound of the heads moving stops, the only sound coming from the drive is that of the spinning disk. All during the time of start-up the LED lights on the hard drive enclosure are rapidly flickering. Once the faint sounds of the heads moving stops the LEDs go to a steady state. Unfortunately, the drive isn't recognized and mounted by any of my computers.
This start-up sequence is identical to that observed for the working, donor drive when I power it up in the same hard drive enclosure except that this drive is recognized and mounted by the computers.
Another observation with the failed, patient drive is that the LED lights of the enclosure will flicker for about 10 - 15 seconds every couple of minutes after the initial start-up sequence described above ... as though the unit is trying to work or is "looking" for something. However, no sounds other than the spinning disk are associated with this.
Oh !

chemshawn wrote:
My take from all of this is that the failed, patient drive is working from a physical standpoint and that the issue is, in fact, related to the PCB.
NO. (At least from what you said and reported symptoms)
chemshawn wrote:
This finally brings me to my question ... does anyone know if it is possible that the reason why the drive isn't being recognized and mounted by the computers is somehow related to the file formatting on the patient / donor drives? In other words, is the firmware chip / electronics somehow placed into a different "setting" or "state" when the drive is formatted for MS-DOS as opposed to a Mac Journaled format?
NO.
chemshawn wrote:
At any rate, I am hoping that someone in the community might happen to have some insight into this as my instinct is that I am close to actually getting the failed drive working long enough to retrieve the data off of it and that there is simply something that I am overlooking.
I would have done something else (not DIYable by you) . The discussion, however, is pointless because expensive tooling and K-H is required either for certain diagnose and eventually for fixing the issue. Unluckily, expenses are unavoidable....