Selfscan on slim drives

[rameez]

I have done alot of selfscan on many drive but one strange thing on slim drives like ATHENA or N40P i started selfscan on these drive the drive were full of bad sectors but reporting size correctly . Then i started selfscan the procedure completed in 8 hours then i chked the drive Athena 2b020h1 <20gb> changed its self to 2b010h1 <10gb> and N40p 6e040l0 <40gb> changed its self to 6e030l0 <30gb> but the hdd became ok the bad sectors were gone .
I did the same thing again on another slim drives i got the same result .

I dont understand why is the serial and the size changing ?

thanks in advance .

[Samo]

I dont understand why is the serial and the size changing ?

If drive have had bad surface and can't manage in Ss to keep the density...
I did not understand whats the strange here.

[BlackST]

Nothing strange : selfscan determined that the drive is no longer reliable as 40 GB but for a 30GB density could be OK then the drive was "re-qualified" for this.
At factory level is normal that drives that fail the quality acceptance for 40GB are re-qualified for 30GB if their behaviour is OK... selfscan is the last step during drive assembly and is and automated procedure for this purpose (and for cutting costs too). Have you ever seen drives with one label over another on the top ?

[rameez]

thankyou for all your answers now i understand what happens . To blackst yes i have seen restickered hdd refurbished .