1. flightrisk's Avatar
    Hi, my Curve has a buzz, seems to be a 60cycle type hum, during the first few seconds of every call. I suspected the screen is causing the hum, and it does seem that I can hit the tracball to make the screen light up and the buzz returns during the call until the backlight goes off. Is this normal or should I take the device back? I just got it and have no BB experience before this.
    12-22-08 01:44 PM
  2. THE_BEANER's Avatar
    hmm... that is kinda strange...


    i have never noticed a buzz sound while using my phone.

    id take that one back if it where me.
    12-22-08 02:00 PM
  3. GmrPnm21's Avatar
    no buzz here! sounds like a wire isn't insulated very well...
    12-22-08 02:01 PM
  4. flightrisk's Avatar
    I too suspected it was a grounding or shielding issue with the pulsing of the lighting system for the screen. I looked up the design specs and can see that these are pulsed white LED backlight systems and the brightness circuit simply turns on and off the driver chip at a rate between 100Hz and 1000Hz. The low end of this is exactly what I was hearing.

    So basically, the screen brightness is controlled by turing it on and off for different durations, but doing it at a rate of at least 100 times a second so you don't see the flicker.

    Bottom line is, new phone, problem is gone

    -f
    12-31-08 03:35 PM
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