[rescue] Rescued Sun servers, now what?!

Mark Benson md.benson at gmail.com
Fri Jun 17 10:44:46 CDT 2011

>>> I tend to use compressed air from a regular air compressor.  The
>>> trick with compressed air is to not let the fans spin.   They're
>>> generators.  Spin em 10x faster than they normally go and they dump 120
volts back into your circuit that normally supplies 12!

> Not really.
> First, many fans, particularly on peecees, have electronics between the
motor and the upstream power feed, circuitry that doesn't pass power
> the wrong way well (or sometimes at all).

While what you are saying may be  true I actually have a much better reason to
jam the fans when using compressed air (I use it at work a lot for de-dusting)
- if you spin cheap PC fans at 10x their design speed it damages the bearings
and about 6 months later they start vibrating. Had it happen to me a few times
until I was told and it hasn't happened since.

Oh, and strictly speaking if you are using compressed atmospheric air on a
conventional tool compressor you should put a moisture trap in the line (used
for paint spraying IIRC) to prevent it spitting water on the board.

Mark Benson


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