Hi everybody,

I wanted to make some test of heads compatibility between to WD10EAVS - 00D7B1 drives.
So I did take 2 drives with the same model but different DCM and product date.
Firs HDD number #1:
WD10EAVS-00D7B1
Date: 03 July 2009
DCM: HANNNT2MAB

Second HDD number #2:

WD10EAVS-00D7B1
Date 12 June 2009
DCM: HHNNNT2CFN

First I did check the drives and see that all was OK reading writing on them was OK, no surface problem after checking with HDD Regenerator.
I connect the drive to PC with an USB to SATA adapter.
Then I did open the drives and check if the heads are the same according to the info writen on them:
On both heads was the same info:

WD-06 1162-100

I do presume this is the info about the heads model so heads must be compatible. I did attach here also picture from them.
No info about the Preamplifier.

I did swap then the heads and after I did mount them back and I did connect both to PC using the USB to SATA adapter.

HDD number #1 did register (ID) him self in Device Manager but that was all. Disk Manager or no other disk managing software could read nothing from the drive.
I did try then to connect the drive to SATA port directly and the same result, only registering but nothing more.

HDD number #2 was reported only like USB device, when was connected to USB to SATA adapter or reported like generic SCSI Device when connected to SATA port directly.

I did then try to connect the HDDs to Data Compass tool presuming that the heads need to be "aligned" or calibrated somehow and I did give a try to Data Compass who should stabilize the heads and put them on track. I have done this cause in the past I did manage to Image some drives whit bad heads, or at least with bad behaving heads, using this product and data recovery was successful.

Even connected to Data Compass no data could be read from drives what so ever.

I presume then that I did damaged the heads during swapping procedure.
So I did mount back the heads to the original HDD and both HDD are working OK again, data can be read and written on both whitout problems, I did made a second check with HDD Regenerator and again no surface damaged found.

Can someone help me and explain why the heads didn't work ?
Can be that even if the info on the heads is the same the heads can be different ? That why I did attach here the pictures.
Can somehow the info about PA to be read using terminal commands ?

Thank you all for future help, best regads, alianu.

Hi everybody,

I must apologize I did post a stupid post.
Now I did saw the differences between the heads. One is WD-06 1162-100 and one is WD-06 1162-000.
For sure there are some differences, and for sure the heads are not the same model.
I must again apologize cause I did spawn the forum with stupid post.

Best regards you all.

There are a few firmware modules that contain information about the heads - 0A, 47, 02, 802E, etc.
No need to open the drives to find out the heads are different.