It is common perception that laptop hard drives are more
prone to failure with time, compared to desktop drives.
What are the opinions of buying a used laptop drive? What
about a used external drive (e.g. desktop internal drive
with enclosure)? Is it more risk than it's worth?

I have the same question about memory for laptops. Are
there typical problems with memory that come up as they age?
I'm not talking about nonvolatile memory, since I know that
they have a shorter lifetime than volatile memory. Just
"normal" RAM. I realize that one can simply see if the
laptop boots up after installing the memory, but if you get
512MB of 2nd hand RAM, that's in the ball park of a CD-R's
worth of bytes. It certainly is possible for there to be
corruption in a CD-R's contents without making itself known
right away. So I'm wondering how likely this is with 2nd
hand RAM, even in the absence of boot-up problems.

Thanks.

I buy used laptop hard drives on E-Bay all the time. NEVER BUY A DRIVE
WHICH THE SELLER DESCRIBES AS "UNTESTED" OR "AS-IS". In E-Bay Land,
"untested" is a euphamism for "it's dead, but if we say that it won't
bring much". [I'd say that it's a euphamism for "it won't sell", but
people actually sell bad laptop hard drives on E-Bay expclicitly saying
that they are bad and, what is even more amazing is that other people
actually buy them, although I have no idea why.] If you buy a drive
from a seller that will guarantee it to be working on arrival, and test
it when it comes in, you should be fine. Check the seller's rating and
feedback as well.

Used memory is much less of a problem. It is almost always good,
usually even when it's listed as "untested".

Test drives with the Hitach DFT (drive fitness test). It can test
non-IBM/Hitachi drives, but it can only low-level format IBM & Hitachi
drives.

Test memory with Memtest or Memtest-86


Dubious Dude wrote:

I'd beg to differ on SODIMM. I bought 3 used, low-density PC100 256MB
SODIMMs and 2 of 3 failed to work reliably. When I have it installed
in my TP600E (requires PC100 low density), the 16-chip version) the TP
would boot up ok, shows the correct installed memory size, and Windows
actually would come up for a couple of minutes, then BSOD (blue screen
of death). The third one to work fine (identical part
number/manufacturer)..

Dubious Dude <Shifty@eyes.com> writes:
I've never heard that, but who cares? Both types of drives fail over time.

New drives are so cheap I don't see much point to buying a used one.

I haven't had heard of any such problems or experienced them myself.
I've had a heck of a lot of HD's fail.

"Paul Rubin" <http://phr.cx@NOSPAM.invalid> wrote in message
news:7xmzgvnkya.fsf@ruckus.brouhaha.com...
Buy memory new. Especially SODIMMs as they endure a lot of heat over time in
laptops and will start getting errors. As I responded in your earlier
thread, I bought some used 256 SODIMMs off ebay and they went bad within a
year.

juliuslr@gmail.com wrote:
There were a number of low-end vendors who cut costs recently by not
bothering to test the memory they were producing. I'd only buy new
memory from a reputable vendor with a good return policy (Kingston,
Crucial, Dell for Dell machines, etc).

Bob Schmidt wrote:
It's all probabilistic, but for example, if the MTBF for a desktop
hard drive is 10 years, while it is 3 years for a laptop hard drive,
then I would probably have 2nd thoughts about getting a used laptop
hard drive.

It depends on one's situation. As well, the newer hard drives are
many times larger than I require.

Thanks for that.

Thanks again, Bob.

Barry Watzman wrote:

Barry, thanks for the suggestions on how to purchase on eBay, and on
testing tools. Dell also provides memory & hard disk testing
applications, though I'm sure that it doesn't hurt to use more than 1
set of tools.

Beyond 100% functionality of goods upon arrival, I was also motivated
to post by my ignorance of lifetimes (or the roughly similar concept
of mean time between failure, or MTBF) for hard drives and memories.
That is, they may test fine upon arrival, but the very fact that they
have been used means that they won't last as long. I was hoping that
enough people would share their experiences on this so that a rough
idea can be had of how likely one is to encounter such limits in
2nd hand memories and hard disks. Thanks for relating your experience
on this.

Dubious Dude <Shifty@eyes.com> writes:
I don't have any reason to think there's any difference. If you want
reliable, get an enterprise SCSI drive and make sure it's kept cool.

http://www.seagate.com/content/docs/...CSI_042003.pdf

William P.N. Smith wrote:
Thanks, Julius and William, for your responses. I'm not too worried
about getting stuck with bum RAMs that fail initial testing, since
I can get the locally and test them on the spot. More at issue is
how much reliable error-free life they have left. But at one quarter
the price of new, perhaps it is practical to simply use them and
replace them when they die. The only concern is whether errors could
be nonfatal or noncatastrophic, and corruption may be saved to disk
for some time before the problem makes itself known.

For a typical end-user, you really don't need to worry about component
lifetimes or failure subsequent to initial good receipt. I'm not saying
that failures don't occur. But they are unpredictable, and compared to
the use of a typical non-commercial end-user, the MTBF's are so long
compared to how much you will use the item, that they are irrelevant.
Memories are semiconductor devices, they will have a typical life, once
past infant mortality, of decades. In many way, you will do better with
used components than with new components, because the used components
have made it past the high-falure "infant mortality" stage. Also, many
memory modules (I'd say most) have a lifetime warranty. I've bought
used laptops and sent back defective modules from Kingston, Extend,
Viking and others and had them replaced with new modules, no questions
asked. Random failures are a fact of life, but they are also
infrequent. These items are quite reliable, and if you get one that is
working, it's unlikely to give you a subsequent problem.

[I'm excluding the cases, such as some models of hard drives, where
there is a systemic design defect that ends up impacting a huge portion
of the entire population of that particular model. This has happened
with a few models of disk drives, and indeed was a factor in IBM's
departure from the disk drive market.]


Dubious Dude wrote:

Barry Watzman wrote:

Barry,

Thanks for the reminder of the infant mortality rate, as well as for
your datapoint on the reliability of used memory & hard drives. The
examples of good memory brand names are also helpful. I've heard
good opinions about Kingston (which you mention)& Shikatronics.