Which of the terminals in the connector plug below are for VC?

That's a valid point. Other than that first time -- when it was mounted inside PC, and failed to start with BIOS--I've only tested it (hence) via an external USB case. I've heard USB is quite limited. Alas, and time-constrained, I haven't tried the myriad drive-test utilities that operate at primitive-level DOS or via BIOS. I've heard that head-stack checks can be turned off for indiv. heads.

I suspect that most people watching this group could care less about LC filters and NPO ceramics, or the fidelity of their subwoofer. As for me, all I care about is helping you get access to your data.

Perhaps jono-ats may be able to work with the little information you have given him, but I can't. I need to see the underside of the PCB.


I'm still waiting. BTW, I've only recently been through this same procedure with someone else, so it shouldn't be too difficult. Unless of course jono-ats can save us all the trouble ...

You did say that the headstack moved backwards on the ramp, so this would suggest that the VCM circuit is intact. It would have helped if you had monitored the actual voltage drop across the sense resistor, especially at the time of the "chirp". Only you know why you have chosen not to do that.

BTW, NPO capacitors are really only necessary in those circuits that require temperature stability, eg VCOs, PLLs. They are of no practical benefit as filter capacitors across a supply rail. Please, whatever you do, don't mention Monster Cable or any more audiophoolery. That kind of talk belongs in other forums, if it belongs anywhere at all.

_________________
A backup a day keeps DR away.

Should be the two adjacent pins on the upper right of the connector. Nominal resistance 6.85-7 ohms.

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http://www.datasaversllc.com

I'm sure you're correct. The higher-quality passives, and select "K" components are used in spacecraft-and military-grade version of HDDs, motherboards and other devices.

?????
UPPER right is 5.9kohm
LOWER right is 7.6ohm

fzabkar: per your request ... Rear of PCB...

Oops ... this should've been 79.3kohm.

Your VCM pins match those of another Hitachi model that I have recently analysed.

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A backup a day keeps DR away.

I checked a head stack that was removed from a Hitachi, and assumed the lettering on the connector had the same orientation as yours on the . Sorry if I erred. Anyway, the two pins in question are adjacent towards an end, and should measure a low value as noted.

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R(VCM)=7.7ohm
When motor has sped up to full (??) RPM, voltage across VCM transients VERY QUICKLY from 0.0V to (roughly)5.0V to 0.0V (concurrent with "click") ... motor idles at full for 5 sec ... click (another VCM trans.) followed immediately by motor decell. to zero.That's on a Win XP PC with this HDD connected via Venus DS2 USB external case.
On a Win 7 laptop, with this HDD connected via Venus DS2 USB external case, the laptop keeps pinging the HDD, so even tho' it clicks (VCM receives brief pwr), the motor never slows down until it is manually powered off or USB cable is unplugged.

Hi,
This could simply be the OS Power Settings. Check in Windows Control Panel-->Power Options for the power profile. go into the power profile and see what it is set for. For example, there is a setting for "Always On" on WinXP or "High performance" for Win 7. you can go to "change settings" and view what the PC will do for the HDD, monitor etc.

May have nothing to do with the Disk itself.

It could also be your AV software trying to scan an inserted disk, or the something to do with file searching.

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

Vm = Lm. di/dt + Rm.i

_________________
A backup a day keeps DR away.

For now, I can only mount this drive in an external USB case. It's an AMS Venus DS3, similar to...

All other drives I have work fine in this case. The defective Hitachi failed at start up -- after 5hrs off time -- in a Win XP system (this was May 2010)--the drive was mounted internally in the PC via usual SATA, and powered by PC's native Antec 750w PSU. I got a relatively close "twin" drive and swapped boards. Nothing, except it spun up with the donor board -- something that I recently got the orig. board to also do (not sure why -- see earlier in this thread). The drive has remained in safe storage until recently. My interest in this drive are only for curiosity/hobbyist reasons. I had backups so was no data was ever lost.

If/when the motor reaches full speed, is this what creates that momentary power-up on VCM (as noted above)?
Put another way, what are the criteria for VCM to receive current?

Also, what is a/the startup procedure for a std. HDD. This may be ...
cardinal:
1. +5v input YES/NO
2. +12v input YES/NO
3. etc.
4. etc.
[...] etc. Success!

And/or logical:

If ____, then ___
else ___

So, something (a missing or erroneous parameter or variable or constant) is missing, active, true, false, etc. This may be related to a damaged component, like an open R, or a cold solder joint, or an internally damaged IC.

SO the drive is still not working ?

How much VCM current did you measure?

What is the resistance of the sense resistor?

_________________
A backup a day keeps DR away.

Ok, back to MY HDD for a moment.....

Eagle eyed user "fzabkar" spotted that black spot on the motor driver IC. And I thought, even though it's not helpful in my case, but it's still interesting to have a closer look. Unfortunately I had no SD card with me and had to take pictures from the screen.

Some notes to the pix:

• On the IC picture I could look down to the metallic chip. That hole is deep!

• Three of the gold bonding wires of the IC evaporated (overheated). The there wires go most likely to the same spot, there were used because of the higher power requirement.

• On the X-Ray picture, under defect is one big air bubble. That could be a assembly/soldering defect. Or the bubble was caused by overheating. It is most likely some heat conductive glue between the IC chip (we call them 'dice') and the metallic leadframe.

Thanks for posting the X-ray pics, very interesting indeed. It would be great to have that level of certainty with alot of other cases

Ditto.

_________________
A backup a day keeps DR away.

We have an X-Ray in one of the assembly factories we work with (to check BGA soldering), but I seldom go there nowadays.

I actually took them at an electronics exhibition (Nepcon) were the demo some X-Ray machinery. Keep that in mind if you want to visit the Productronica in Munich in November. And be smarter then me and bring a USB stick!

Coming back to my problem, does the HDD sound give any clue?

https://dl.dropboxusercontent.com/u/25666483/Memo.mp3