newguy,

Listen to me...
The periodical >3ms blocks because heads seeking from one track to the next one.

Your drive have head at the right place, i am sure about this, because if one head is missing, your drive model can't init at all, so you will not see in BIOS or in MHDD.

Anyway, your platter have some damage, and if you force the drive to read this area or even slide on the top of damaged area only one second is enough for head crash, and the next some second is enough for move all your data into the internal filter....

You need precisely diagnose the problem, and not like this way, what we do (trying to figure out your scenarion by your information) and needs special equipment, like pepe sad, and read the drive head by head.
You can't do this without a lot of experience and a lot of expensive tools.
So, again, (and last time) if your data is important, don't gamble with it, search someone who can help you for reasonable price.
... or destroy your drive in the way what you want, but please don't wast the others time to posting here...

Janos

If the head was 'hanging on a wire' as u said, and scratching the surface, u would not be able to read a single sector from the drive, nor would it have quite normal sounds...
Anyway, if u think it is beyond your capabilities, find a pro near you. As far as I am concerned I think that would be a wise idea at this point.

the sound indicates it is having reading problems, probably caused by slight platter damage. I have seen many of these.

pepe

_________________
Adatmentés - Data recovery

Hi all;
Thanks for your concern! I won't poke around at it more and will consider using a DR service if it is warranted.

However I would also like to learn (like when I bring my car in for repair; they always explain to me what is going on as best they can; of course sometimes they have to open it up and see and I understand that takes time and money and specialized tools).

However; what I don't understand about what both of you said is: don't most drives (or at least this drive) have multiple heads and platters? What if the 3rd head down the stack broke/fell off/whatever? Wouldn't I be getting some blocks of data just fine(i.e. blocks read by heads # 0, 1, and 4) and others are unrecoverable errors (i.e. any block read by head #2)??

So I don't understand why a single failed head in a stack (unless it's the one for the System Area) would cause the whole drive to not work.

NC: You said specifically "because if one head is missing, your drive model can't init at all, so you will not see in BIOS or in MHDD". Does this model have a firmware function that shuts down all functionality if a single head is bad? (Seems like an odd 'feature' to have)

Pepe: I agree, I would think there would be a very odd noise if a head were falling off and contacting the platter. But you also say I wouldn't be able to read the drive (wouldnt the other heads still read?)

One philosophical question; let's say there's some platter damage. What possible way could there be to read the drive without causing more damage? (Regardless of how expensive or specialized the tool is)?

For example, let's say the damage is somewhere on the outer edge of a platter; maybe a reverse read would help since it will grab all the 'good' data at the 'end' of the drive. But to get the inner tracks, the heads will have to slide across the bad area. Isn't this bad no matter how you do it?

Thanks again to everyone for the help.

your drive probably has 2 heads.
the drive measures MR resistance at startup and if it falls out of its prefered interval, heads are not even unparked.
Of course there can be a level of damage when it is still not too bad, but can only read slowly.
These are states a pro can diagnose precisely in minutes, but you lack both the equipment and the knowledge to do it.
That's why I advised to look for a pro.
Knowing at least your state (preferably the city) would help finding someone nearby...

pepe

_________________
Adatmentés - Data recovery

Ah ha!
Thanks Pepe for that, it is good/interesting to know.

FYI I am an EE (Electrical Engineer) and have a dual degree in Physics so none of this is beyond me... when it's explained to me. Of course, I lack the experience and expensive tools to do this as a business, but it is just interesting to me to learn how it is done.

You say the drive probably has 2 heads; meaning a single platter?

PS I am in New York, USA; but not in NYC, I am about 2 hours/100 miles north.

But I would still like to know; if the problem is a damaged platter... and reading over the damaged area could make things worse... then how does (even a professional) identify the boundaries of the damaged area and read only the good data before and after it?

Thanks again

thats probably more of a "trade secret" than anyone is going to want to talk about

_________________
You don't have to backup all of your files, just the ones you want to keep.

If you go in to the shop, and buy any brand, new and smallest size HDD, most likely you will get one drive with one platter and with 1 or 2 heads.

Loosing one head:
The behavior is different, and it depends on many things.
The most intelligent drive will spin up, and will not move the heads. (like yours)
The most of the other drives can't do the initial (basic)recalibration with one failing head, and will fall to endless knocking.
(No head-> no servo -> no position information -> the head will moving uncontrolled)
The others will do some knock and than spins down.
And at the very end, there is some dirve modell wich can get readyness with one failing head and will fall to knocking when the windows booting from it.



How to do recovery on damaged drives?
This is a deep trade secret on any company.

Janos

Similar to your example, if one good car service person only can hear something, the most of the cases knows what he needs to do without touching the car.
This called experience.

We seeing similar cases day by day, and we have the experience for safely do what we need to do.
We have worked out (electrical/mechanical/software-)tricks, special tools and special softwares, and so on...

We can do sector copy from this drive, and we can recognize in the second, if the head gets on the top of damaged area, or if the MR's condition gets more worse, and we can skip this head area for one time or for the whole recovery or jump with the MHA to anoter location and continue the copying safely elsewher....

Janos

I have located a few DR firms but how do I tell which ones are sufficiently advanced to do a good job and which ones are just some guy in his basement using the same tools I already have access to?

PS: If the head is OK, what would cause platter damage? Can the head hit the platter once, and damage just the platter and not the head itself? This drive was running fine for years until it completely died. I hadn't noticed any of the degredation, unexplained freezing/hanging/weird noises that one typically experiences with a HDD that is on it's way out...

What do you call OK?
The head can get some particles from the surface and the sensitivity decreased.
After 90% decrease, no longer gets the servo labels, and will start strange noises and in the end knocking.

When the head hits the platter more things can be happening...
- The head gets overheated
- the particles gets into the head's face
- the head can crash
- the platter can damaged in one circle or elliptic notches
- if the head was in write state, the magnetic domains gets moved including the servo labels

A pro who working on HDD should recognize all without opening the top lid....

Janos

The guys who do a good job will have success cases that you can verify!

DR is not like repairing cars. The patients and the objectives are vastly different.