AlphaServer 4100 CPU fan

[Adrian Graham]

Hi,

>Do the original fans have speed sensors?  There were several different
versions of this.  Some fans have an OK signal, some give a pulse once per
rev.  Did the original fans have 3 wires?

Yes, I put them down as +12V, GND, Pulse.

Original fan: http://f0p.co.uk/AS4100original.JPG
Replacement: http://f0p.co.uk/AS4100replacement.JPG

I'm guessing the original was slightly more 'special' than the replacement
which is just a cooling fan...

Cheers

Adrian

On 20 July 2015 at 16:17, Jon Elson <elson at pico-systems.com> wrote:

> On 07/20/2015 09:23 AM, Adrian Graham wrote:
>
>> Folks,
>>
>> I didn't realise there'd been a clasiccmp server meltdown, wondered why I
>> wasn't getting mails :)
>>
>> We still have a few AS4100s out there in the field and CPU fans are
>> becoming scarce, so being canny we sourced some *almost* identical
>> replacements to no avail.
>>
>> Original spec for the fan is 12V 0.17A, our replacements are 12V 0.18A and
>> the console still reports them as failed. I've sanity checked by using a
>> processor board with a good fan and still nothing. Could the 0.01A cause
>> THAT much of an issue? The wiring is a good 3" longer too but I didn't
>> think that would cause problems either.
>>
>>
>>  Do the original fans have speed sensors?  There were several different
> versions of this.  Some fans have an OK signal, some give a pulse once per
> rev.  Did the original fans have 3 wires?
>
> Jon
>



-- 
adrian/witchy
Owner of Binary Dinosaurs, the UK's biggest home computer collection?
www.binarydinosaurs.co.uk