Low frequency shaking sound when backlight is off

Very starnge.  It only happens for certain MP3 song, and when the backlight goes off, I can hear very clearly some low frequency (about 3-4 Hz) of poping sound comes out.  Once I press a key and the backlight goes back on, the pop disappear.

I have the same problem, only it seems to be present in several (if not all) songs.  It’s a motorboating noise.

Are your files vbr mp3s? if so, I had the same problem:


Activate the custom equalizer to see if it disappears.

Yes, at first I thought it was drum beating at the background, but then I realized that drum cannot beat that fast.

This is kind of an annoying bug, because the beating sound appear louder in some songs and not as loud in others, and other songs cannot hear that at all.  But why would turning on the backlight will fix this beating sound ??


The killer files is a CBR at 128 kbps, 44 kHz sampling rate.

I will try different EQ setting to see if it fixes the problem.

@hyiu00 wrote:

  But why would turning on the backlight will fix this beating sound ??

There’s a post from Sansafix somewhere explaining that the player looks at the MP3 it’s about to play and decides how slowly it can clock the CPU while still decoding the file. It’s a battery saving tactic. Sometimes it gets it wrong and cuts the clock too agressively, resulting in poor playback.

Turning on the light (i.e. driving the display) or using the custom EQ causes the clock speed to be ramped up, and the file then plays OK.

Supposed to be fixed in the next firmware, I believe.

A workround is to use the custom EQ setting. I’m not sure whether you have to have a non-flat profile to work. I have +1 on the top frequency.

Yes, after changing the EQ to “Rock” from “Normal”, the problem is fixed.  I don’t even need to use “custom” for the EQ.  This problem makes me very carefully listern to the background music/noise.

Yes, this fixed the problem for me, as well.  Thanks!

Message Edited by dgibsonky on 12-04-2008 05:04 PM