Clicking after WD PCB Swap - Wrong motor controller?

[zed]

Hi All,

I have a WD5000KS-00MNB0 hard disk which a suspected PCB fault (drive would not spin up) but the motor controller or no other chips appeared burnt.

I found an identical hard disk with the exactly the same model #, the same PCB/board # (1st 13 characters matched) BUT the only visible difference when looking at the chips was that the motor controller on the faulty PCB said "SMOOTH L6284 2.2" BUT the donor/new pcb has printed ""SMOOTH L6284*2.2"" - just this additiona' *' symbol is the difference.

After a PCB swap (and swapping the rom chip) the faulty disk with the new PCB powers up then 'click click'.....'click click'....'click click' then powers off. It waits a few seconds then powers on and repeats this clicking and powering off/on and does not get detected. I don't want to assume it's a damaged pre-amp or head as the pcb did not really look damaged at all - simply would not power up.

Has anybody done a PCB swap for a WD5000KS series hard disk and had it work? If so - do you think this * difference on the smooth chip makes the new board incompatible as everything else looks like an EXACT match and even the DCM code is EXACTLY the same on both drives and the drives are made only 2 days apart (e.g August 2 and August 4, 2006).

Any ideas on what the problem could be? Why didn't this work?

See attached a photo of the faulty PCB (missing the rom chip in this photo as it was removed for the pcb swap).

Any tips or suggestions would be greatly apreciated. I am wanting to leave a head swap as a last resort, i am thinking it may not be needed.

Thanks for any help.

Attachments

Photo of faulty PCB with missing rom chip.

[badboy]

sometime it couldn't be detected after hot swapping. i guess it caused by some rom information or some other similar information.

But according to your description, it sound "clicking". it sould be the head damaged. if the data are very important for you i suggest you can send it to the professional data recovery company.

[BlackST]

Head or preamp bad.

[N.C.]

Hello, Zed

I can see in the picture, you have soldered, the RAM too.
Why?
Are you sure, this is ok now?
The * symbol not important.

The problem can be:

1. preamp damage (you can measure this)
2. different code in the mcu
3. soldering problem on the ROM or RAM. (you can measure this also)

I suggest, don't do the head swap before an exactly proper diagnosing!
If you unsure, go to pro...

Regards,
Janos

[Rev Engineer]

Is there any publicly available info regarding head swaps and alignment on these WD drives?

[zed]

Thanks all for the replies - N.C, i swapped the ram as a last resort when the rom swap did not fix the problem.

I usually would not do this but had nothing to loose so gave it a try!

May i ask - how would you measure pre-amp damage?

[qwerty]

zed.. i have similar problem with my WD2500KS hdd. have u solved your prob now? mind to share with me? PM me pls
N.C.. how to measure a dead preamp?

[beto]

Hy zed on this models, u cannot did an PCB swap , because has adaptive information over microcontroller, we got some cases like that WD5000AAKS used same Model, an day of difference, on Data, and sam MDL ,knocks the cause, the microcontroller was damaged and was not possible to did an copy of ROM, but maybe would be possible on the next update

Regards

[zed]

I'm afraid I never found a solution. I was going to try a head swap.

[qwerty]

Hy zed on this models, u cannot did an PCB swap , because has adaptive information over microcontroller, we got some cases like that WD5000AAKS used same Model, an day of difference, on Data, and sam MDL ,knocks the cause, the microcontroller was damaged and was not possible to did an copy of ROM, but maybe would be possible on the next update

Regards

beto.. what about WD2500KS-00MJB0 ? have any info on this model? i did a ROM swap too but same occured like zed did

[jono-ats]

Beto: The latest UDMA update supports this (Zeus) model.

[beto]

Hy jono ,thanks for the info

regards

[zed]

beto, so what's the solution for these kinds of drives? Do you have to do a PCB swap with a drive made on the EXACT same day?

[pcrecovery]

Zed,

Since your original PCB won't even power on drive at all, before I try head swap, I would test your board thoroughly. Were you able to backup the ROM and MODULES in kernel mode? You should be able to read their contents, even if not on the drive. Also, if you can't read the bad board, but you can read the good one, I'd recommend you measure some voltage drops and look at some scope readings, as my vote is for a bad 88i6545 chip. Would explain symptoms as well.