OK, I have to apologize for this, but after spending some time in the garage mucking around, it appears to me that the decimal point on my (Chinese made) Craftsman VOM is malfunctioning, and the meter is giving inconsistent readings. I will need to throw that thing back in their face on my next visit to Sears.

I pulled out the next best thing, an even cheaper Taiwanese Harbor Freight model, and repeated all the measurements again. Hopefully these are more believable. All measurements are in Ohms, and internal resistance of the meter was observed to be about 1 Ohm.

Drive 1
--------
D3 - 508
D4 - 1
R67 - 1
R64 - 122
Vneg - 85
Vcore - 85
2V5 - 1
3V3 - 1
5V - 508

Drive 2
--------
D3 - 35
D4 - 1
R67 - 1
R64 - Infinite
Vneg - 110
Vcore - 1.8
2V5 - 1.5
3V3 - 1.3
5V - 35

Does that seem more realistic? Since the PCB's are blown, they are of course not connected to a power source during the measurements.

In the event that these make more sense, I must repeat my question in hopes of a more definitive answer: "In terms of rebuilding the ROM from the SA, is that something which should be relatively straightforward if one licenses a full copy of WDMarvel for a month? Are there any how-to docs that you've seen that detail this process? Or am I best off not mucking with it and just sending it off for someone more knowledgable to tackle?"

Keetah, if I had a working backup, I would not be here now. One drive was the other's backup, and no others exist. It's my wife's computer. I tell her to get an oil change and she does not, so cloud backups are certainly not high on her to do list. Maybe now...

ianc

I understand about the backups. It's always after the fact that people choose to get a backup strategy going. I've seen this play out a thousand times before.

I also learned that if something is beyond my reach and capability it's best to get pro-level help by people whom have done before what I'm trying to do now.

If I actually want to learn it, then I'll go and practice on non-valuable stuff first to get the lay of the land. This applies to file management as well as repairing real physical things. The next best solution is learning hands-on with an instructor nearby to stop you from mucking up the works. And while that could work here I believe there are many subtleties that need to be gained from real experience. It will be frustrating at best.

Most people quickly develop a rabid desire to learn anything and everything about data recovery as soon as their only copy of whatever data goes belly-up. Especially when the price exceeds $300-$400. And it's a one-time gig. They don't really care about "data recovery". That's evidenced by waning interest in the subject once they get their data back. If they get their data back.

These days I do little recovery work. And as time rolls on I'll outsource more recoveries. My focus has shifted to prevention and ensuring backups are in place. When they are, anybody and everybody suddenly becomes their own Sunday morning data recovery technician.

_________________
On a clear disk you can seek forever.

Here are what I believe to be the supply pins for the preamp:

Please confirm that there is continuity between each of the 3 pads and its respective test point on the PCB (Vneg = -5V). I would use a good PCB for these measurements. It would also be advisable to repeat the previous resistance measurements on the good PCB.

Now locate the corresponding pins at the HDA connector on the body of the HDD. Measure the resistance between pin 2 and each of pin 4 and 6. If the resistance is too low, then the preamp will be shorted.

_________________
A backup a day keeps DR away.

Hi fzabkar,

I've made the previous measurements on the good replacement PCB. They are:

D3 - infinite
D4 - infinite
R64 - 1
R67 - 1
Vneg - 87
Vcore - 43
2V5 - infinite
3V3 - infinite
5V - infinite

All measurements were made only at the 200 Ohm scale, and internal R was again observed to be about 1 Ohm.

As far as continuity, I only found it between pad 6 and Vneg on any of the boards. None of the boards had connectivity between pads 2 and 4 and Vneg. I was a little confused by your instructions, but I'm assuming Vneg is the solitary pin on the right side of the component near the drive connector as shown in your picture on the previous page.

Resistance between pin 2 & 4 and pin 2 & 6 on both drives was larger than 200 Ohms.

Thanks again for your attention,

ianc

The preamps are probably OK. If they were damaged, then the drives would either not spin up, or spin up, click a bit, and then spin down again. At least that's my understanding. I was hoping to measure the preamp resistances and compare the two dead drives. If the results were close, then that would have given us some added confidence.

I'll get back to you in a while.

_________________
A backup a day keeps DR away.