Re: gEDA-user: buzzing board

[DJ Delorie <dj@xxxxxxxxxxx>]

> The OLED has noise on it 0.5V.  What frequency?

Line redraw noise is about 7.8khz, with the waveform dependent on
what's on the screen.  That's the high pitched whine portion.

5.5ms of that noise, followed by 1.5ms of quiet, about 140Hz vertical
refresh.  That's the buzzing portion.

> The switchers are opporating at 150KHz.
> 
> What frequency is the buzzing?

Audible :-(

> Could a capacitor be humming like a tunning fork with respect to one or
> more of the noise signals?

I've tried removing, and changing, the bypass cap on that supply rail.
No change.

Hmmm... I can try tweaking the refresh period.  As soon as my son is
done playing video games with my laptop.


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