April 5th, 2012, 1:22
fzabkar wrote: I assume that you have not attempted to spin up the 2TB HDDs with the IBM PCB, so the 2TB motors would still be suspect.
fzabkar wrote:That said, are you using compatible boards for your testing? One scenario that would fit the symptoms would be if your boards had different pinouts for the motor connector. For example, one could be wired as A/B/C/Common, whereas the other could be Common/B/C/A. The last thing you would want is for your motor to spin backwards.
April 5th, 2012, 3:07
April 5th, 2012, 3:54
April 5th, 2012, 5:13
woxy wrote:... because 2TB Hitachi PCB spinned up IBM motor just for a while,
when old Hitachi spinned IBM as long as powered ...
April 5th, 2012, 7:14
woxy wrote:Hi all,
I'm looking for NVRAM for those drives. I've got 3 of them and all suffers from same, trying to start but only makes only bzz bzz for few times. Then motor driver IC is getting hot. I'm assuming corrupted firmware.
woxy wrote: I've tryied like with Seagate but got nothing on telnet.
April 5th, 2012, 8:02
BlackST wrote:1) This is SalvationData support forum
BlackST wrote:2) Even if you get the NVRAM content from another one, it likely won't work or will work partially (if you have SD tools or any other tool and/or you know how Hitachi / IBM work, you know why)
BlackST wrote:3) The problem is elsewhere.
April 6th, 2012, 5:13
April 6th, 2012, 16:03
April 6th, 2012, 17:27
woxy wrote:I've disassembled whole hdd.
Weird thing is that with original 2TB PCB and also with IBM PCB, hdd motor spinned up
only when all platers of hdd was removed. When platers putted again, none of PCB
spinned up motor, looked like motor didn't have strength to run with platers ballast.
Conclusion, somehow 2TB motor is faulty, even though multimeter didn't show anything wrong
with windings, and motor runs easily by hand (so no stucked bearings), because
none of PCB's spinned up motor with platers attached. And as the motor can't be easily replaced,
last 2 Hitachi's will be sold as donors.
Not a DIY problem unfortunately.
April 7th, 2012, 7:01
fzabkar wrote:At the risk of opening an old wound, here is one of my first posts to this forum:
missing-vcm-current-sense-resistor-servo-calibration-t13400.html
It was greeted with the kind of derision that was customary for that time, but I now feel that you may be able to achieve something by at least experimenting with the motor current sense resistor(s), if you can find it/them. For example, if you add a resistor in parallel with the existing one, then you will effectively be increasing the current drive to the motor.
Hopefully my tutorial will show you what to look for:
http://www.users.on.net/~fzabkar/HDD/Tu ... 0411N.html
BlackST wrote:Hint : Why replace the motor ? ?
April 7th, 2012, 16:58
April 7th, 2012, 17:15
woxy wrote:If 2TB Hitachi PCB's are all able to run IBM motor, and MCU is cool, so PCB's are fine (at least as for IBM motor).
April 7th, 2012, 18:48
April 8th, 2012, 8:59
fzabkar wrote:BTW, I should add that a great tool for testing windings for shorted turns is Bob Parker's ESR meter (http://members.ozemail.com.au/~bobpar/esrmeter.htm). It is available in kit form. Although it was designed for measuring the ESR of electrolytic capacitors in-circuit (in which case it has little application in HDD work), it is also an ideal tool for the stated purpose. In fact I find it more convenient than an inductance meter.
For example, the resistances of the windings on a motor in a WD1600BB drive measure approximately 0.8 ohms on a multimeter, whereas my ESR meter reads 33 ohms (phase-to-phase). This is because it injects an 8us pulse into the component being tested, so inductances look more like reactances than resistances.woxy wrote:If 2TB Hitachi PCB's are all able to run IBM motor, and MCU is cool, so PCB's are fine (at least as for IBM motor).
I suspect that you are referring to the motor controller, not the MCU (the main microcontroller).
April 8th, 2012, 12:12
fzabkar wrote:The component that I have identified as "???" looks like a capacitor, but I'm not certain.
April 10th, 2012, 9:25
+12V
o
|
|
+---------+----------+
| |
| |
||-+ +-||
||<- Q1 Q3 ->||
---||-+ +-||---
| |
| |
o----)-------+ |
| ___ | |
o---+--|___|-+--o VCM o--+---o
| current |
| sense |
||-+ +-||
||<- Q2 Q4 ->||
---||-+ +-||---
| |
| |
+---------+----------+
|
|
===
GNDApril 10th, 2012, 13:43
fzabkar wrote:I've looked at your results several times, but I still can't see how your board senses motor current. I would have liked to see the voltage on each of the spindle sense pins, but probing these points with a multimeter has a very high risk of catastrophic damage. If your multimeter's probe tip is too large, you could try affixing a sewing needle to the end. At the very least, it would be useful to know the resistances between each pin and ground.
April 10th, 2012, 17:24
April 16th, 2012, 5:56

April 17th, 2012, 17:00
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