Date   : Tue, 14 Dec 2010 23:32:13 +0100
From   : kortink@... (John Kortink)
Subject: Harddisc fakery using a microcontroller

On Tue, 14 Dec 2010 21:05:13 +0000, Wookie <bbcmicro@...>
wrote:

>On 29/11/10 15:29, John Kortink wrote:
>>
>> Don't ditch hard drives that seem to have died just because of
>> a powering error (e.g. 12V on the 5V line).
>>
>> Many drives are protected against this with a 'transil', which
>> very quickly shorts the power line to ground if it exceeds the
>> expected voltage. Unfortunately, this is a permanent condition.
>> But when the transil is removed, the drive will most likely be
>> fine. Replacing the transil is sort-of optional, since the drive
>> itself will function fine without it.
>>
>>
>> John Kortink
>>
>
>What do these "transil's" look like ?

Like this :

http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1578892

(see technical datasheet for a more telling picture)

>and are they on the data lines as well ?

I don't think so. It would be hard to get excessive
voltages on anything but the power lines.

>Ages ago was using a 3.5" to 2.5" cable to connect a laptop IDE drive to 
>a desktop machine and like a idiot I plugged the cable into the laptop 
>drive upside down and sent the power into the data pins, bingo one dead 
>drive.

That's very similar to what I did ... %-(


John Kortink

-- 

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