Help again friends peter, marc, starling, jono, sean, DF..!

[beto]

Hello friend´s and HDDguru´s


Now its me again asking for u help hddguru´s on the before´s cases WD400BB with knocking sound problem was solved and sucess get 100% of data and the FUjitsu MHU knocking , too but now i have another very strange case this is the story!


WD100BB-75AU1 when arrive to my hands was showing the typical syntomph knock contiusly, so i tried to check electronic problem and no have, then try to access SA by bypass to the read channel, and was sucess send DRDY DSC and tried to check SA, and the answer was all SA with ERROR COPY 0 COPY1 Modules, all BAD!!. So i tried the another option head exchange with very closest Donnor HDD; Same Year, Same Month, Same DCM, Same MDL , check again , and still knocking, so im tried to put patiend heads on Donnor MHA, and recalibrate DRDY DSC, was detected by BIOS try to check SA all OK, tried to read sectors all OK; So patient heads its not the problem .

Tried now to do a hot swap with donnor and still knock´s , try to access again bypassing to the read channel and knock, now i cant reach the DRDY DSC, and cant access.

Tell me what can i try to get access to SA, because or its SA Damaged or its Servo Mark Problem!

Thanks all

Sinceraly

Alberto

[jono-ats]

Beto,

On the BB & EB series, the head stack is aligned in conjuction with the top cover plate. This is explained in the HDDGURU article about changing a head stack: http://hddguru.com/content/en/articles/ ... k-Q-and-A/

Sometimes, even removing the cover to peek inside changes the alignment. Other times, the head stack creeps out of alignment all by itself, maybe due to thermal cycling.

If you replace the head stack, it must be aligned relative to the top cover. In other words, you cannot expect to swap heads and expect it to work without finding the correct zenith and azumuth for the head stack to find track zero.

The process for re-alignment is VERY tedious (in your language, un dolor en el culo)! I am in the process of building a prototype jig for making this job easier and more precise. I hope to have some news by the end of the month.

In the meantime, I suggest you read the above article and try to find the proper alignment.

Buena suerte,

Jon

[pepe]

Hello Jon,

head alignment is only important in multi-headed drives. (BTW the alignment of heads realative to eachother is important. As U move the cover, the MHA's axis is tilted slightly, producing a tiny skew between the heads...)

Alberto's drive has 1 head, so it is not the case here.

I suspect the platter might be off-centered by an impact, or servo/data is completely destroyed by a defective preamp or PCB. I met similar thing in IBM AVVA/AVVN drives.

regards,
pepe

[jono-ats]

Pepe,

How do you know Alberto's drive has just one head? The WD400BB I just opened a few minutes ago has a pair of heads and one platter.

Did I misread Alberto's post?

Jon

[pepe]

Hi,

we talked on MSN...

pepe

[beto]

Hello friends

jono this is not WD400BB this is WD100BB 10GB this 40gbwas the before case and now was recoverd But now the problems its on this 10GB

I had tried now to return Donnor heads to Donnor HDA, and still its working, and reading sectors, but on patient still, the problem:(

Do u think a Platter exchange would be help?

Thanks
Sinceraly

Alberto