WD20EZRX PCB DAMAGED

[gps31]

Can I use Donor 2060-771945-002 REV A for the burned pcb patient 2060-771945-001 REV P1

By Transferring ROM Chip? both pcbs are from WD20EZRX HDD

[gps31]

When i tried it just spin up then spin down not detected.


Please any suggestion?

[pepe]

what was the issue with the original board?

[gps31]

Burned PCB

WD20EZRX_Burned.jpg (75.41 KiB) Viewed 13036 times

[data-medics]

It may or may not work. I'd look at the main controller chip to see if it's the same. It all really depends on what was revised, if it's just a different brand of RAM or slightly different motor control chip, it'll probably still work.

[pepe]

Most probably preamp is dead. If you are lucky, the fw checked preamp id before moving heads and decided not to move it.
If you are less lucky, it moved heads and rearranged the data a bit.

see viewtopic.php?t=31493&f=1&start=0#p219267

pepe

[fzabkar]

Most probably preamp is dead. If you are lucky, the fw checked preamp id before moving heads and decided not to move it.
If you are less lucky, it moved heads and rearranged the data a bit.

see viewtopic.php?t=31493&f=1&start=0#p219267

pepe

That statement is misleading. It implies that a dead preamp always fails in such a way as to write on the platters as the headstack sweeps across the disc. As your fellow data recovery professional states in that other thread, such a circumstance is "extremely rare". Morever, the words that you use are loaded.

By way of analogy, let's assume that the chance of being killed in an air crash is one in a million (which is extremely conservative). If 100 million passengers arrive safely at their destinations, we would not say that they were lucky. However, we might say that they were not unlucky. Conversely, if 100 passengers are killed in air accidents, then we would say that they were unlucky. The meaning is entirely different. Moreover, nobody would say, if you value your life, don't fly.

[pepe]

Of course we might argue on this matter from thread to thread, I only want to point out that checking the preamp is a better idea than just hope it will not kill our data.
Out of curiousity, how many recoveries have you done?
The chance is a lot higher than the example you brought. Let's say 1 out of 20 preamp damages will cause data damage if not treated properly. We might say we don't care about 5% of the cases, we are still at 95% success rate as long as preamp damages are concerned, but let's play with the situation a bit.
Suppose you had such a drive, bring it to some DR firm for recovery (i know it would never happen in reality, but let's suppose).
Let's suppose it fails into the 5 % of preamp failures where it kills the data and they do not care about checking the preamp and kill YOUR data out of neglect.
How would you react if they said 'we were lazy to check the preamp and your data is in bad shape'?
It does not matter if they say so, you would know it was the case because you are good in electronics and you would be somewhat angry with them depending on your temper and depending on the value of the data they just killed by ignorance or out of neglect.

My question is if we can reduce the risk why not do it?

pepe

[fzabkar]

In about 6 years of DR iv seen 1 case with a maxtor drive where damaged preamp seemed to wreak havoc with servo tracks. Maybe a handfull of dead PCBs killed by a preamp. All in all preamplifier damage is very rare in our lab. Extremely rare.

1 case in 6 years is not even remotely close to 5%.

[pepe]

it is not your experience, please tell us how many recoveries have You done altogether.
(we have no idea how many Alexii did over 6 years either)
But it makes me nervous how he handled them. ('we have enough donor pcbs, so let's just try and see if it smokes or not')
kindof similar how Stalin thought of people... ouch...

[pepe]

To the OP: Please excuse us to hijack your topic in such way, it seems i can't make a comment without getting a banned by Franc

[fzabkar]

Let's look at the question of your rogue, data destructive preamp from an end user's perspective. If we accept your claims, then the user will have a 5% chance of data loss when faced with the OP's predicament. Let's say the user wants to eliminate this uncertainty by engaging a data recovery professional. However, if he chooses one at random, what are his chances of finding one who knows enough electronics to be able to test a preamp? I can show you numerous threads where experienced forum members have disdainfully told me that they don't need to understand electronics, they only need to swap ROMs. With this in mind, would a figure of 1% be too conservative?

If we accept this figure, and assuming that all of these experienced pros will share your concerns and will actually test the preamp, then the end user who has a rogue preamp will have, at best, a 99% chance of data loss. That's essentially no better than a DIY outcome.

[pepe]

We agree that we disagree anybody who says DR has nothing to do with electronics. As such, it is a pity there are DR firms not able to test a preamp if the pcb is blown. This may as well reduce the chance as you said. BTW, my posts might draw attention to the problem, if they are not misinterpreted.

However, users should be warned for this possibility at least when suggesting a DIY solution.

If we accept this figure, and assuming that all of these experienced pros will share your concerns and will actually test the preamp, then the end user who has a rogue preamp will have, at best, a 99% chance of data loss. That's essentially no better than a DIY outcome.

I don't get it. If the drive gets to a pro's hands who tests the preamp, why would there be 99% chance of data loss?
Am i missing something?

pepe

[fzabkar]

Sorry, my post was ambiguous. I'm suggesting that a drive with a known rogue preamp that is sent to a randomly selected DR firm would have a 99% chance of data loss simply because 99% of DR firms would not test for this case, either because they don't know how to, or because they don't deem it to be necessary.

Perhaps a better way to put it would be to say that an end user would reduce his chances for data loss from 5% to 4.95% if he chose a DR firm at random instead of doing the job himself.

[pepe]

Now that we are all aware of the "problem" (despite the fact that everyone here for years suggested to replace PCB/ROM without this pre-amp check to be even mentioned), what do you suggest for people to do (apart from sending the drive to you) and i'm not just talking about DIY people, i'm talking about the majority of experienced pros as well ?!

2 - Pepe doesn't describe how to reliable test the pre-amp with cheap tools available to someone attempting DIY sollutions.

When i was active on this forum i posted some info about how to check the preamp with cheap tools, of course now i don't only rely on that method, but the majority of preamp damages can be filtered with a multimeter.
Around 2006 or so.

Sure the pre-amp can be bad when the PCB is replaces and cause damage ...... but let's not forget that the computer might have a virus that will kill the data, the mcu on the pcb might not be working properly and damage data, the sata interface, the motherboard, etc ... might have a problem ... etc ....

Don't write bullshit, we are talking about a specific problem and its proper treatment.

It will be fun to see how data recovery pros will react now that the Ace forum is open to the general public

And this is morally questionable to cut open such a forum. Users were posting info there in the belief there is a limited audience. They shared knowledge with eachother and not with the world. They were urged to share info. Now it is cut open, it's like shooting somebody from the back. Nobody will post info there either.

[data-medics]

For once, I have to say I totally agree with Fzabkar... Even if the preamp is damaged from the surge that blew the PCB, it's very unlikely that it'll damage the platters. Unless the data on there is literally going to cost you your life to lose it, I'd say go ahead with replacing the PCB. If it did damage in such a way that it's going to damage the platters, chances are the damage is already done regardless.

@Pepe, chill out. I'm starting to see why you were banned.

[pepe]

hances are the damage is already done regardless.

it depends on wether the drive was working at the moment of the surge. If it was powered off, the data is safe until u power ir up with the bad preamp.
If it was working, it might have caused some damage, like 1-2 sweeps, but the more u play with it, the more damaged it will be.

Btw, I don't feel like i have to chill out, i have no emotional relation to anybody's drives.

[fzabkar]

For once, I have to say I totally agree with Fzabkar...

Actually, I agree with pepe on one point. If you can test the preamp, then do it. I would, but that's because I always attempt to determine the full nature of the problem in order to select the most appropriate solution. I would hate to burn a replacement PCB because I neglected to at least test for shorts on the +5V and -5V supply rails. That would require less than a minute of my time. In fact there are plenty of threads where I have demonstrated how to do this.

My primary issue with his statements is that they imply that end users should not attempt DIY recovery, but should send their drives to professionals, presumably because professionals would perform the required testing. Clearly, this is not true, and the user would be essentially no better off.

As for the claims of 5%, or 1 case in 6 years, that is something that you and others can assess for yourselves.