Any Good Links on How to Test Motor Windngs?

[ddrecovery]

I have a Seagate ST3000DM001. The computer it was in was in a flood while it was powered on. The drive was dead. I have replaced the board with a donor (with ROM swap). If I isolate the HDA I can get the board DRD and I can read the board ID, so I don't think its a ROM issue. Is there any good reference material on how to correctly test the motor windings. There are a few links in this forum, but most are now no longer live. Any help would be appreciated.

[thatdellguy]

1. Did liquid get into the inside? First thing we do with a flooded drive is look inside. Replacing the circuit board without knowing the condition inside is irresponsible and reckless.
2. Motor is checked with DVOM, pretty basic stuff...

[fzabkar]

There are a few links in this forum, but most are now no longer live.

Which links are they?

A quick and dirty test is to measure the resistances between each pair of terminals. These should be of the order of 1 or 2 ohms. Depending on the number of terminals, the phase-to-phase resistance should be twice the phase-to-common resistance.

A DC test won't always detect shorted turns. For that you would need an inductance meter.

An oscilloscope would be even better ...

http://nazyura.hardw.net/MotGood.jpg
http://nazyura.hardw.net/MotoBad.jpg

[ddrecovery]

1. Did liquid get into the inside? First thing we do with a flooded drive is look inside. Replacing the circuit board without knowing the condition inside is irresponsible and reckless.
2. Motor is checked with DVOM, pretty basic stuff...

Boy you do like to jump down peoples throats before asking questions. The drive was at the top of the workstation and did not get wet. The drive has been opened and checked. No water damage. Its our 4th water damaged drive this month due to severe weather. Two were under water and have got over 90% of the data on both. I know how to use a multi-meter, but its the specifics of checking the windings in this particular situation. As I have told you before, I am not afraid of asking dumb questions (I am sure you are pleased to hear), the clients data is the most important thing and others may learn something too.

[ddrecovery]

There are a few links in this forum, but most are now no longer live.

Which links are they?

I will take another look for the links, I know one was to Seagate. Thanks for the advice.

[fzabkar]

FYI, you can measure the motor current with a multimeter.

Measuring VCM and Spindle Motor Current:
http://malthus.zapto.org/viewtopic.php?f=59&t=204&p=484

[ddrecovery]

FYI, you can measure the motor current with a multimeter.

Measuring VCM and Spindle Motor Current:
http://malthus.zapto.org/viewtopic.php?f=59&t=204&p=484

Perfect.

[northwind]

1. Did liquid get into the inside? First thing we do with a flooded drive is look inside. Replacing the circuit board without knowing the condition inside is irresponsible and reckless.
2. Motor is checked with DVOM, pretty basic stuff...

Boy you do like to jump down peoples throats before asking questions. The drive was at the top of the workstation and did not get wet. The drive has been opened and checked. No water damage. Its our 4th water damaged drive this month due to severe weather. Two were under water and have got over 90% of the data on both. I know how to use a multi-meter, but its the specifics of checking the windings in this particular situation. As I have told you before, I am not afraid of asking dumb questions (I am sure you are pleased to hear), the clients data is the most important thing and others may learn something too.

thatdellguy's concern was valid.
You said:

The computer it was in was in a flood while it was powered on. The drive was dead.

which would mean to me that maybe the drive was soaked. Which would mean that water probably got inside, which would mean... etc.

The drive was at the top of the workstation and did not get wet. The drive has been opened and checked. No water damage.

That wasn't clarified at the beginning and it is very important information.

[ddrecovery]

@Northwind - I totally appreciate your comments. The initial question topic was about testing motor windings not about recovering a drive that had been in water, so I kind of assumed you knew I would have opened the drive.

[northwind]

I never assume anything

[ddrecovery]

Measuring VCM and Spindle Motor Current:
http://malthus.zapto.org/viewtopic.php?f=59&t=204&p=484

Thanks for the link, very comprehensive indeed. I am trying my best to absorb it, but need a little help relating it to my board. I have tested the windings at the three points and they all show 2.9 ohms. I am having difficult locating and testing the VCM points. Can you steer me in the right direction?

Attachments

[fzabkar]

The only likely looking current sense resistor appears to be the one marked "R221". If it senses VCM current, then it will have continuity with the VCM pins (15 and 17 ?) at J4. Otherwise, if it senses spindle motor current, then one end will be grounded.

That said, I notice that some newer boards, and some not so new Hitachis, appear to sense the spindle motor current internally to the motor controller. I suspect these designs use senseFETs, in which case I don't believe there is any easy, non-invasive way to measure the motor current.

Some light reading ...

http://www.onsemi.com/pub_link/Collateral/AND8093-D.PDF
http://www.eetasia.com/STATIC/PDF/20080 ... S=DOWNLOAD
http://www.nxp.com/documents/applicatio ... N10322.pdf

BTW, I'm not suggesting that any information I've provided has any bearing on your actual problem. I'm merely answering your questions ...

[ddrecovery]

Thanks you

[ddrecovery]

You may have seen a post from me about getting a drive in that had been to another data recovery company viewtopic.php?f=1&t=29453

Toshiba MK5065GSXF
The ROM chip on the left was on the board when it came to me. The ROM chip on the right is the ROM chip from my donor (exact match in terms of Make, SN# MD# board# etc). I know from the client that the other DR company said the ROM chip was dead and they had tried a 'similar dated ROM chip' to see if that would work!! They have told my client that the original ROM was on the board they gave back to the client. However the donor and patient ROM chips are significantly different. Is there any way of telling if this chip is supplied to this board/drive? If this is not the patient ROM, then as its a Toshiba the data is toast (maybe anyway with a dead ROM).

[fzabkar]

Could we see the contents of each chip?

The date code on the ST Microelectronics chip is obscured (xx25K ?).

I'm not sure about the Sanyo chip, but its date/batch code appears to be 043A98. Japanese manufacturers often depart from the usual YWW or YYWW encoding, but my guess would be that 043 is the YWW code.

Both chips appear to be 4M-bit (512Kx8), 2.3V - 3.6V, serial flash memories.

That said, I'm not sure that knowing the date codes would help because Japanese manufacturers often hold stock for as long as a year, whereas US manufacturers such as WD and Seagate move stock very quickly. This means that the ICs on US made PCBs tend to have closely matched date codes while the date codes on Japanese PCBs may vary greatly. I would be very concerned if the date code on any IC was more recent that the manufacture date of the HDD, though.

[ddrecovery]

I have just ordered a programmer, so should be able to post whats left of the patient ROM soon. As far as the date code is concerned, there is a substance burnt onto the ROM surface that is impossible to remove. Probably Flux thats been reheated numerous times. As best as I cab see there is only one additional number and it seems to be a 3 ie 325K.

[fzabkar]

As best as I can see there is only one additional number and it seems to be a 3 ie 325K.

"1325K" or "325K" would suggest that the chip was manufactured during the 25th week of 2013.

That said, I'm getting a little confused by the direction this thread is taking. First Seagate, now Toshiba ???

BTW, Japanese manufacturers tend to source their ICs from other Japanese manufacturers, so an ST Microelectronics part might raise an eyebrow.

[biggerpizza]

Measuring VCM and Spindle Motor Current:
http://malthus.zapto.org/viewtopic.php?f=59&t=204&p=484

Thanks for the link, very comprehensive indeed. I am trying my best to absorb it, but need a little help relating it to my board. I have tested the windings at the three points and they all show 2.9 ohms. I am having difficult locating and testing the VCM points. Can you steer me in the right direction?

The resistance of winding looks fine which means the winding should be ok.

[labtech]

One of my drives:
MDL: MK5065GSXF
PCB: G002706A
ROM looks your donor's on the right hand side you posted with codes:
25U406B
SA1 VP
041A74

My conclusion - someone did not what they were doing prior to sending to you.