HI,

Martin Paul wrote:
> All of my Blade 1500 workstations (blue) generate a strange kind of howling
> noise. Taking a close look with the case opened, I know now that it's
> caused by the case fans, which accelerate/decelerate about once or twice
> per second - one can hear that, and even see it when looking at the
> fan blades.
>
> One can see it in prtdiag -v output, too. I used:
>
> while test 1 = 1
> do
> date
> prtdiag -v | egrep 'rpm|Ambient'
> done
>
> The temperature is constant, but the fan rpm of both case fans is changing
> frequently. I guess the problem could easily be solved in software, by
> modifying the fan speed control. Is it possible to do this via any Solaris
> command (picl/*fru*/whatever) ? I'd really like to check whether e.g.
> setting the fans to a fixed rpm would resolve the noise problem.
>
> If nothing else, I'd like to know if anybody else has this problem.
>
> Running the fans on full-speed all the time would probably be less
> disturbing than this pulsating sound.
>
> I'm up-to-date on patches, and I just updated the OBP to the most recent
> version, too (I hoped this could help, esp. after seeing "4816966: Need to
> change Fan PWM Freq in OBP for Taco" in the OBP patch README, but to no
> avail).
>
> mp.
I have this also on a Blade 1500 silver.


/michael