Damaged sectors

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Cristiano

After a scandisk scan under Win7 (Properties -> Tools -> Check now...)
of a 2 years old external ST3500418AS (power on: 350 hours), the SMART
shows 4079 "unstable sectors" (the scan took 3 days).

Can the box adapter cause that kind of problems? I mean no filter,
inadequate current, fluctuating voltage, ...

Thanks
Cristiano
 
Cristiano said:
After a scandisk scan under Win7 (Properties -> Tools -> Check now...)
of a 2 years old external ST3500418AS (power on: 350 hours), the SMART
shows 4079 "unstable sectors" (the scan took 3 days).
Click to expand...
Can the box adapter cause that kind of problems? I mean no filter,
inadequate current, fluctuating voltage, ...
Click to expand...

Yes, it can. Although typically they are regulated, very well
filtered, deliver enough current, etc. Still, sometimes
they break like everything else.

In my experience however, what you see is typically for a drive
that has suffered excessive mechnical shock or excessive, prolonged
heat. The power adapter is likely far more resilient than any
other part.

Arno
 
Cristiano said:
After a scandisk scan under Win7 (Properties -> Tools -> Check now...)
Click to expand...

I believe the last time "scandisk" was found included with Windows was
back in Windows 9x/ME. NT-based versions of Windows have chkdsk.exe.

Have you tried running chkdsk.exe? Open a command prompt and enter
"chkdsk c: /r" (assuming that C: is the drive with Windows on it). That
requires you reboot the machine so the partition is no inuse by the OS
if and when surface errors need to be corrected.

http://www.w7forums.com/use-chkdsk-check-disk-t448.html

I suspect the GUI form's "Scan for and attempt recovery of bad sectors"
is equivalent to the /r command-line switch; however, it may only imply
the less corrective /f switch. You want to use the /r switch to test
the surfaces of your hard disk's platters.
of a 2 years old external ST3500418AS (power on: 350 hours),
the SMART shows 4079 "unstable sectors" (the scan took 3 days).
Click to expand...

"the SMART shows" where? CHKDSK doesn't show that. What did you use to
retrieve the SMART data from the hard disk? What does the rest of the
SMART data say, like the Current Pending Sector Count?

The scan took 3 days. What scan? CHKDSK scans. Anything retrieving
the SMART data does so immediately (there's no "scanning" to get that
info).
Can the box adapter cause that kind of problems? I mean no filter,
inadequate current, fluctuating voltage, ...
Click to expand...

Get Seagate's Seatools to check the condition of your hard disk. I'd
get the DOS version to boot from a CD to run the program outside of
Windows (so Windows isn't running during the testing).

http://www.seagate.com/support/downloads/seatools/
 
Cristiano said:
After a scandisk scan under Win7 (Properties -> Tools -> Check now...)
of a 2 years old external ST3500418AS (power on: 350 hours), the SMART
shows 4079 "unstable sectors" (the scan took 3 days).
Click to expand...
Can the box adapter cause that kind of problems?
I mean no filter, inadequate current, fluctuating voltage, ...
Click to expand...

Yes, its possible. The obvious test is to remove the drive
from the external housing and see if you get the same
result with the drive installed internally in the PC.
 
Arno said:
Yes, it can. Although typically they are regulated, very well
filtered, deliver enough current, etc. Still, sometimes
they break like everything else.

In my experience however, what you see is typically for a drive
that has suffered excessive mechnical shock or excessive, prolonged
heat.
Click to expand...
The power adapter is likely far more resilient than any other part.
Click to expand...

That last is just plain wrong with the cheapest external drives.
 
The power adapter is likely far more resilient than any
other part.
Click to expand...

Here's a link to a 2MB photo (sorry about the size) of
power adapters included with various USB drive enclosures.

The top row photos are of a UL approved model DA-30C01 power
adapter by Asian Power Devices and included with an Iomega
USB hard disk. It's rated for +5V @ 1.5A and +12V @ 1.5A.

The middle photos are of the non-approved power adapter from a
Bytecc enclosure but is also used by Vantec and apparently
many other enclosure makers. There's no brand name, but it's
model SPP34--12.0/5.0-2000 and is rated for slightly more
power than the previous power adapter, +5V @ 2.0A and +12V @
2.0A, despite the transformer being no bigger and the main
filter capacitor being 68uF instead of 47uF. Oddly, its Y
capacitor (blue thing below the transformer, labelled CY1) is
UL approved while the Y capacitor in the UL approved PSU is
not UL approved. Also this power adapter uses a 3-wire AC
cord, but apparently it offers no safety benefits because the
cord's ground connection goes to a circuit board pad connected
to nothing.

At the bottom is what could be the worst power supply. It
was in a Neo enclosure, and the low voltage USB-IDE adapter
circuit board to the left normally sat just above, separated
only with a piece of thin but fairly tough plastic (pressed
against the heatsink with the high voltage transistors on it
). I don't see any overvoltage protection, and one customer's
hard disk blew out after a week of use (drive chip burned, left scorch mark on bottom of enclosure). I don't know if the drive
was bad or if the power supply caused the damage, but he the
dealer gave him a full refund and a replacement drive. They
gave me a full refund and paid for return shipping. They also
quickly changed their website to remove the claims of UL approval.


http://img208.imageshack.us/img208/9057/usbenclosurespowersuppl.jpg
 
After a scandisk scan under Win7
(Properties -> Tools -> Check now...)
of a 2 years old external ST3500418AS (power on:
350 hours), the SMART shows 4079 "unstable sectors"
(the scan took 3 days). Can the box adapter cause
that kind of problems? I mean no filter, inadequate
current, fluctuating voltage, ... Thanks Cristiano
Click to expand...

You may want to run MHDD (self booting) or HDDscan (Windows),
available at HDDguru.com, because they can run SMART tests on
many USB drives. And whether you test through the USB adapter
or connect the internal drive directly to a SATA port, these
programs can indicate which sectors are hard to read (need
multiple read attempt). However HDDscan seems to give many false positives for this, maybe because of Windows overhead (even if
the hard disk isn't the one containing Windows). OTOH MHDD
seems to have problems with drives bigger than about 1TB. BTW
it seems normal for some model hard drives to show a couple of
really slow sectors (need > 150ms to read) per terabyte. I
saw this with the Samsung 2TB HD204UI, the 2TB Hitachi (but not
the 1TB), and Seagate 7200.12. OTOH I've never seen a WD showing
any slow sectors, the exception being one my friend knocked over
while it was running.
 
Here's a link to a 2MB photo (sorry about the size) of
power adapters included with various USB drive enclosures.
Click to expand...
The top row photos are of a UL approved model DA-30C01 power
adapter by Asian Power Devices and included with an Iomega
USB hard disk. It's rated for +5V @ 1.5A and +12V @ 1.5A.
Click to expand...
The middle photos are of the non-approved power adapter from a [...]
At the bottom is what could be the worst power supply. It
Click to expand...
[...]

Urgh. I had no idea non-approved PSUs were even legal to sell.
(They are not here...) Well, if the OP has one of the bad ones,
that could definitely cause the problem. Especially if the
output filter cap blew.

Arno
 
(e-mail address removed) wrote:
Click to expand...
On Monday, November 26, 2012 6:42:07 AM UTC-7, Arno wrote:

The power adapter is likely far more resilient than any other
part.


Urgh. I had no idea non-approved PSUs were even legal to sell.
(They are not here...) Well, if the OP has one of the bad ones,
that could definitely cause the problem. Especially if the output
filter cap blew. Arno
Click to expand...

I don't know if the picture I posted came through, so here's a repost:

http://www1.picturepush.com/photo/a/11504419/1024/Anonymous/USB-enclosures-power-supplies.jpg
 
Here's a link to a 2MB photo (sorry about the size) of
power adapters included with various USB drive enclosures.
Click to expand...

I read "Ktec" and "OUTPUT: 12 V 2.0 A" in the box adapter and I don't
see any UL mark (I see the CE mark).

The shape of the adapter can be the one labeled "UL approved AC adapter"
in your photo, but how could I know?

Thank you very much for the photo and the explanation.
Cristiano
 
After a scandisk scan under Win7 (Properties -> Tools ->
Check now...) of a 2 years old external ST3500418AS (power
on: 350 hours), the SMART shows 4079 "unstable sectors"
(the scan took 3 days).

Can the box adapter cause that kind of problems? I mean
no filter, inadequate current, fluctuating voltage, ...

I read "Ktec" and "OUTPUT: 12 V 2.0 A" in the box adapter
and I don't see any UL mark (I see the CE mark). The shape
of the adapter can be the one labeled "UL approved AC
adapter" in your photo, but how could I know?
Click to expand...

If that Ktec adapter was furnished by Seagate, I would expect it
to be very high quality and meets all safety standards, even
those if it's not tested for. It's possible it's not UL approved simply because it's not meant for sale in the US, although UL has certifications that apply for other countries. If you ever need
to buy another box adapter, find something with the safety certifications printed on the Ktec's label.
 
I read "Ktec" and "OUTPUT: 12 V 2.0 A" in the box adapter and I don't
see any UL mark (I see the CE mark).

The shape of the adapter can be the one labeled "UL approved AC adapter"
in your photo, but how could I know?

Thank you very much for the photo and the explanation.
Cristiano
Click to expand...

Which CE mark? The real EU version or the less real China Export version?

Grant.
 
If that Ktec adapter was furnished by Seagate, I would expect it
to be very high quality and meets all safety standards, even
those if it's not tested for.
Click to expand...

The adapter is bundled in the fantec box package.

Cristiano
 
You may want to run MHDD (self booting) or HDDscan (Windows),
available at HDDguru.com, because they can run SMART tests on
many USB drives. And whether you test through the USB adapter
or connect the internal drive directly to a SATA port, these
programs can indicate which sectors are hard to read (need
multiple read attempt). However HDDscan seems to give many false positives for this, maybe because of Windows overhead (even if
the hard disk isn't the one containing Windows). OTOH MHDD
seems to have problems with drives bigger than about 1TB. BTW
it seems normal for some model hard drives to show a couple of
really slow sectors (need > 150ms to read) per terabyte. I
saw this with the Samsung 2TB HD204UI, the 2TB Hitachi (but not
the 1TB), and Seagate 7200.12. OTOH I've never seen a WD showing
any slow sectors, the exception being one my friend knocked over
while it was running.
Click to expand...

MHDD seems a bit "critical", while HDDScan seems unreliable (the time
needed to read a sector is different each time I run the program, even
with a good HD).

I tried my own program which read the disk sectors and I get 8 to 17 ms
(with USB 2.0 cable), but occasionally I get >300 ms on the bad disk.
But I still haven't read all the sectors...

Cristiano
 
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