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Wharfedale LCD37f1080p struggles to wakeup from standby.

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    Wharfedale LCD37f1080p struggles to wakeup from standby.

    As mentioned in the thread title, my 37" Wharfedale TV struggles to wake up from standby.
    On plugging into the wall, the power LED will blink for a while (duration varies from minutes to hours). Trying to wake it up gets no response.
    Once I get a steady light, I can start trying to bring it out of standby. Pressing a button will, if it's warm, wake up the TV. If it's cold, or the TV has been off for a while, the power light will blink off, the screen may flicker on, the speakers may pop before the light comes back on and it goes back into standby.
    As I said, the problem seems affected by temperature. If the room is cold, it takes ages to get things going. If it's very warm, things seem fine.
    I don't know if this is connected, but there is nearly always a constant buzz coming from the speakers. It only goes away if the volume is set to zero - the buzz is otherwise unaffected by the volume controls.
    Once I get it up and running, it works fine.
    The power board is a 17PW20 V2, which I gather from reading other posts, are known for being problematic.
    I identified two caps - C818 and C857 - as being close to failure. The tops are noticeably bulging.
    I've ordered replacements and I'm confident I can get them in okay.
    Am on the right track? Could faulty caps at the positions I've identified cause problems like this?
    Another thought I had was, could it be possible to just completely bypass the Standby section of the board, so the power switch just turns the thing on?
    Would this be doable, and how complicated might it be?

    Hi everyone! I'm very glad I found this place.

    --S

    #2
    Re: Wharfedale LCD37f1080p struggles to wakeup from standby.

    The standby circuit is need to turn the rest of the power supply on, so it can't really be bypassed. It is also likely some of the small electrolytics are also bad, but being small without vents you can't tell by looking at them. Post clear in focus pictures of the board
    It looks like C818 & C857 are on the 3.3 volt standby lines, I would also replace C860 & C830 if they are on that board
    and C817 & C838 for the +5Vstby
    Also replace C892 (10µf/50v) & C801 (33µf/50v)
    Note: some of these boards are very different and some components are not used on some versions
    Last edited by R_J; 03-02-2019, 05:13 PM.

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