2488 LCD panel noise

Discussion in '2488 and DP-24/32 Digital Portastudios' started by johnjohn, Sep 26, 2021.

  1. johnjohn

    johnjohn New Member

    Joined:
    Oct 2018
    Messages:
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    Gear:
    2488
    I don't know if this is typical of all 2488 units but mine has always had a faint high pitch whining sound. This sound also breaks though as electrical noise on the Guitar (H) input when using a high gain effect.

    Anyway I decided to track down the source of the whine. I thought that it was a vibrating inductor or capacitor in the power supply but after careful listening it seemed to be coming from behind the LCD screen.

    So I tried disconnecting the LCD screen and the noise was gone. Then I reconnected the LCD, disconnected the power wires for the electroluminescent backlight, and again the noise was gone.

    This means the problem is related to the EL panel in the LCD screen.

    Since I have a HGR 2488 VGA Monitor kit installed I don't really use the LCD so I cut the A & K wires that provide power to the EL panel. This means the LCD no longer has a backlight, though it is still readable in a well lite room .

    Anyway this may be of use to anyone else who experiences the same problem.
    Last edited: Sep 27, 2021
    -mjk-, Logrinn and dctdct like this.
  2. Mark Richards

    Mark Richards Well-Known Member

    Joined:
    Dec 2017
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    From:
    USA
    Gear:
    DP-24 Portastudio
    Thanks for investigating and posting the results.:)
    -mjk- likes this.
  3. -mjk-

    -mjk- Moderator Staff Member

    Joined:
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    From:
    Hukou Township, Hsinchu County, Taiwan
    Gear:
    DP-32, | 2A Mixer, A3440
    @johnjohn said:

    I think you could probably add a snap-on choke to get rid of that RFI. I would try that for sure.