High pitch noise when screen is set to 40% brightness or higher?

retroman80s

Member
Jan 17, 2011
5
0
my coby tablet seems to make a low high pitch noise when my screen is set to ~40% or greater brightness. I've noticed it when I'm sitting in a quiet room trying to read. If I turn down the brightness to less than 40%, the noise is gone.

Anyone notice this on their Coby Kyros?
 

gurgle

Super Moderator
Staff member
Aug 6, 2010
1,463
131
You sound like you have a floating ground problem on your circuitboard creating either direct or RF noise. It is likely there. You cannot hear it until you get the brightness above 40%.
This is a defect in my opinion and should have the device returned/exchanged.

btw:if you do not know what a floating ground problem is: Here is the definition define:Floating ground - Google Search
This is usually a loose connection or partially soldered board.
 

retroman80s

Member
Jan 17, 2011
5
0
You sound like you have a floating ground problem on your circuitboard creating either direct or RF noise. It is likely there. You cannot hear it until you get the brightness above 40%.
This is a defect in my opinion and should have the device returned/exchanged.

btw:if you do not know what a floating ground problem is: Here is the definition define:Floating ground - Google Search
This is usually a loose connection or partially soldered board.

thank gurgle. I wasn't sure if anyone else has this issue, it's not loud but it is noticeable sitting in a quiet room. I can even hear the noise through my headphones even when i turn the volume to 0 !!!

I guess I'll do a factory reset and get it exchanged.
 

willber

Member
Jan 9, 2011
147
1
or you have supper hearing.... often dimming can cause these sorts of higher harmonic artifacts as the dimming of the fluorescent panel ( I don't believe the 7015 is LED technology) is done by chopping up the power cycle to the light panel.
At any rate I'll listen to mine tonight and see. Gurgle's point should be taken as you may truly have a wonky unit.
 

BKenney

Member
Dec 10, 2010
138
5
I've got the brightness all the way up on mine, and with my ear right next to the device I still don't hear anything.
 

retroman80s

Member
Jan 17, 2011
5
0
I've got the brightness all the way up on mine, and with my ear right next to the device I still don't hear anything.
Thanks BKenney, can you plug in your headphones, turn the volume to 0 and see if you hear any high pitch noise.
 
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