Seagate motor question

[Hexed]

I have a ST3300831A with a seized spindle motor bearing. It's a 7200.8. Typically I always purchase good, working, matching drives to use as part drives. In this case though, I am wondering if I really have to. The heads were in the park zone when I opened it and I do not see any signs of media damage or head slaps at all. It has been my experience in the past that usually the original heads are still good in a case like this. Anyways, I have a whole bunch of dead Seagate drives with good motors. I don't however have any of the same model or even any that are 7200.8. Would it be acceptable to use a chasis from a 7200.*. Any idea of what requirements a drive would have to meet to be a suitable chasis/motor donor.

[Russwinters]

I would still match the chassis with that series.


Also it never hurts to have backup parts.

[jono-ats]

I've been able to loosen the bearings and recover the data from this series of Seagate w/o having to do a platter swap.

[Hexed]

So far I have not been able to free the bearing. I think I will work in that direction some more though. It's 3 platters, 6 heads so after a platters swap. it's going to be a pain to image anyway. If that doesn't work, I'll just order a matching drive. I am confident that one of the drive chasis I have would work fine but after the swap, if the drive does not initialize and give me access, I can't be wondering if it is an incompatible motor issue. I'll also need to be able to test the client heads in the donor drive so I don't have to worry about them either. I will be able to just start the allignment game.

[Hexed]

Well I got the original motor spinning again. It is a bit noisy and there is some vibration but it does not seem too bad. The drive does not come ready though, busy forever.
Terminal shows:
Interface task reset
4096k x 16 buffer detected
TONKA - 1_Disk S.00 03-10-05 16:38

Buzz - Head Mask FFFF - Switch to full int.
Spin Ready
Nothing more happens after that.

Good drive (different model obviously):
Interface task reset
4096k x 16 SDRAM
TONKA2 - 1_Disk M-31 12-07-05 09:13

Buzz - Head Mask FFFF - Switch to full int.
Spin Ready
(P)PATA Reset
Master

I am thinking there is still too much vibration. Anybody agree or disagree?

[Hexed]

I tried waiting a bit longer to see if the drive would come ready. After about 30 seconds, terminal reports:
Interface task reset
4096k x 16 buffer detected
TONKA - 1_Disk S.00 03-10-05 16:38

Buzz - Head Mask FFFF - Switch to full int.
Spin Ready
Error Reading Application Code

Certainly vibration no?

[Russwinters]

Well that means that it cannot read the firmware area of the disk.

Could me: Damaged/incompatible heads, Media damage, platter alignment, eccentricity (not in that order)


Those are the 4 areas I would look into

[Hexed]

Thanks for the replies Russ. I am ordering a matching part drive today. The heads can't be incompatible as they are the original heads. I realize that not all media damage is visible but I do not see any at all and have no reason to suspect there is any. The filter is clean too. I also don't see any damage to the heads under microscope. When I get my part drive, I will prove the heads good. At this point, I feel the problem is vibration. I mainly think this because when the heads lift off, they go to a service track and just stay there. No clicking or repeating terminal errors. Failed heads don't typically act that way. There is also a chance of platter alignment. I don't know of any way to prove this but I have had a theory for some time now that when a drives platters spinning at 7200RPM come to a sudden stop, they can shift. I hope that is not the case though. I'll let you know in a few days what I find out when I get my part drive to work with.

[Russwinters]

If you can move heads to your other drive and they work, and also you can sort of the eccentricity (Vibration) then you will know if the problem is alignment or not.


Please keep us updated with your progress!


Regards,

[Hexed]

I will update you when i get my part drive. I did just notice the the drive is definitely eccentric No but really, when I rotate the platters by hand, I can clearly see the wobble. Since I have a bunch of dead drives with good motors, I am going to spend the weekend exploring pulling the hub from the motor and try to press on another one. I have been wanting to try this for a while now. If it looks like it will work, I'll try it on some good drives. If that works, I may even try it on the client drive. I am not optimistic though. If it was a viable solution, everybody would be doing it that way.

[N.C.]

Thanks for the replies Russ. I am ordering a matching part drive today. The heads can't be incompatible as they are the original heads. I realize that not all media damage is visible but I do not see any at all and have no reason to suspect there is any. The filter is clean too. I also don't see any damage to the heads under microscope. When I get my part drive, I will prove the heads good. At this point, I feel the problem is vibration. I mainly think this because when the heads lift off, they go to a service track and just stay there. No clicking or repeating terminal errors. Failed heads don't typically act that way. There is also a chance of platter alignment. I don't know of any way to prove this but I have had a theory for some time now that when a drives platters spinning at 7200RPM come to a sudden stop, they can shift. I hope that is not the case though. I'll let you know in a few days what I find out when I get my part drive to work with.

This is the vibration issue.
The bearing's axis is damaged, and gets off-centered. (eccentric)
Additionally, yes, you have right, when the drive was dropped, the platters can be moved from the center.
For sudden-stop case: i don't think they can shift.

I can help, if you out of the options, but keep this in mind, the vibrating platter can destroy the heads, and the heads can scratch up the media as well....
So, don't play too much, i suggest...

Janos

[withyou]

Hi Friend ,
As Per my experience i always prefer to rectify the problem with orignal componenent as if i get some Read wite head problem than i always prefer to repair with 1:100 usb microscope as many time there is only and only problems with X/Y/Z axis /minor allignment if head is not broken or having more than that but i prefer the orignal hard drive with the orignal component to rerieve the data back.as regarding the donor drive selection 20%of the time we get the refurbuished hard drive with same model no ,part no,firmware,DCM no..
as may be the problem with x/y/z axis or flying hight problem is there , as described by you ,if read write heads seems look physically good

[Hexed]

First attempt at removing hub failed miserably. I made what was basically a miniature gear puller. The hub is on the spindle so tight, I broke my tool without even budging the hub from the spindle. This makes me think once I do get it removed, putting it on another spindle may not be possible. Working on it though.

[withyou]

Hi Friend,
If thats your first case than dont do it yourself as if you dont have numerious tools as if you want to recover the data than you are having numerious tools and perfect infrastructure as this field require lot of things for succesful data recovery as this is not the perfect answer but i suggest for one hard drive or if you want to study than ask i am always with you...

[Hexed]

withyou, not my first case. I am not aware of anyone though that has tools to remove platters and hub as one assembly and press it on to spindle in donor chasis. I am starting to see why now too. But the bottom line is that 3 or more platters swapping sucks. Even if you maintain the platters alignment 110% with relation to each other, there is still usually issues just from the tolerance between the platters and the hub. The ideal situation would be to move the platters and hub together but I am pretty sure now that that can not be done. From what I just tried (on a dead drive obviously) even if you could get the hub off of the old spindle, getting it pressed on a new one would either break the new motor or you would end up damaging the media in the process. And then there would be the height issue. Nope, I don't see it working. Just going to have to swap the platters the old fashioned way if I can't reduce the eccentricity somewhat.

[BlackST]

Not true. Refine your method(s) and eventually tools, and you'll see it work.

[withyou]

Hi Friend,
As you replace the platters and may be in the process to ramp the read write head the read write heads are not getting proper flying hight/gap .
so try and check with same good hard drive and analyze the proper gap/hight to make more experiece as thats good for analyze..

[withyou]

Or may be there are some small rectification with proper Read write Head Allgnment..so please check as you are the best judge with the Hard Drive..

[N.C.]

Hexed,

This case is simple.
You need to move the platters together with a special tool to another motor and than solve the eccentricity.
If the platter gets centered again, and not makes vibration, the drive will init again.

note: there is no warranty for the tracks are in center when the platter itself is in center!
But the most important is the platter needs to be in center, because the rotated weight WILL do vibration wich can destroy the heads + surface.
The track-finding is the positining system's job.

Janos

[withyou]

Hexed,

This case is simple.
You need to move the platters together with a special tool to another motor and than solve the eccentricity.
If the platter gets centered again, and not makes vibration, the drive will init again.

note: there is no warranty for the tracks are in center when the platter itself is in center!
But the most important is the platter needs to be in center, because the rotated weight WILL do vibration wich can destroy the heads + surface.
The track-finding is the positining system's job.

Janos

Hi Friend,
After getting proper donor drive and after the proper replacement of platters we cant get any vibrations as we replace the platters with good donor drive as in droped hard drive case the spindle motor is having vibrations and humming noise but not in good one with proper donor drive selection ...
But please describe as thats good answer with simple problem and the rectification as you describe..
The track-finding is the positining system's ...
As we want to increase our knowledge with this system ..