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resetting BIOS from motherboard

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Lorenz.zulu

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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:
68t386.png
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.
 
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D.A.(Tony)Stewart

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That is the correct (PROCEDURE). The leakage decay time is in seconds to tens of seconds.

On some MOBO's there is a 3 pin jumper near the battery which can be serve this purpose by moving the jumper and toggling power. ( removal then insert charger then revert switch)
 

andre_luis

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should I get this result with a simple screwdriver and with motherboard completely off, without Power supply and batteries connected?

Perhaps needless to mention, but considering that jumper J5 is directly connected to the RTC 3.3v power bus, it is important don't forget to use bracelet with anti-static grounding in order to avoid damage to the circuit.
 

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