A failing RTC/CMOS battery can cause certain hardware to not appear

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  • japlytic
    Badcaps Legend
    • Oct 2005
    • 2086
    • Australia
    #1

    A failing RTC/CMOS battery can cause certain hardware to not appear

    On a Dell Studio Slim 540s, I sometimes had the problem of certain hardware sometimes not appearing under certain circumstances , such as the USB 3.0 expansion card in the PCIe slot, and even an onboard device being the 1394 controller, despite the latest known BIOS update being installed - at one stage, the computer could not display video from the video card in its PCIe slot, despite OS loading activity.
    When I lubricated and reseated the devices on the connectors in question, I took the opportunity to check the RTC/CMOS battery - it was at 2.7V and warranted replacement.
    So far, a new battery fixed this problem, and you may be aware that many modern PCs store PNP (Plug & Play) information in battery-backed extended CMOS RAM (2KB to 4KB, possibly more) - apparently, corrupt PNP information was causing the devices in question not to be recognized under certain circumstances.
    My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.
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