resetting BIOS from motherboard

Discussion in 'General Electronics Chat' started by solarium, Sep 9, 2015.

  1. solarium

    Thread Starter New Member

    Sep 9, 2015
    Hi everybody!
    Trying to fix some problems concerning the main fan of a laptop, I was advised to reset the BIOS. I knew that normally disconnecting the BIOS battery is sufficient to do this task, but I was asked to short a couple of pins for 30 seconds with motherboard off, so without Power supply, laptop battery and BIOS battery.
    Components to short: JOPEN or capacitors C194 and C195 or diode D27 (Cathode and ground or anode and ground). See the following diagram:
    Should I expect with this procedure to reset all the BIOS settings, cancelling even the altered bytes (including data not accessible from the bios menu)?
    And should I get this result with a simple screwdriver and with motherboard completely off, without Power supply and batteries connected?
    Please, someone tell me something about BIOS resetting techniques.
  2. dl324

    Distinguished Member

    Mar 30, 2015
    Shorting J1 will clear CMOS settings so the computer will boot with defaults from BIOS, but it will not clear (reset) BIOS. BIOS is in nonvolatile memory so it doesn't require battery backup. You can reset to factory BIOS settings in setup.