TechSpot

Risky Attempt at Resetting BIOS

By mteamix
Apr 29, 2014
Post New Reply
  1. I'm about to do something risky.
    To some, this "risk" might sound trivial and outright stupid but please bear with me.

    I'll have to reset BIOS settings of my laptop because the screen is not getting any data from my mobo, resulting into a constantly empty screen.
    Reading the online manual of the laptop, the instructions sound quite dangerous to me.

    They involve shorting CMOS jumpers.
    Specifically, by continually shorting the jumpers AND plugging in the AC current and waiting for bios POST, all that while keeping the jumpies shorted.

    Few years ago I burnt a desktop motherboard by a similar practice, shorting + AC current. Regardless, the experience was rather alarming.
    The issue occurred upon exploring BIOS environment, I changed the value of "default monitor something something" into "auto", it previously had another value but I couldn't remember which of the 5-6 different values it was, so 'auto' seemed like a decent choice.

    Since that was my only change, I trivially saved the new setting and restarting I found a pitch black screen that would persist no matter what for these past few days.
    Obviously the mobo is feeding the info elsewhere and not my screen.
    I tried VGA and HDMI outputs in hopes the "auto" mode shifted toward them, but that didn't work out.

    I tried all the typical ways to reset bios, like getting the battery out, CMOS battery out, waiting, casual shorting, more waiting, pressing power button in such and such manner etc etc.
    Now my last resort seems to be doing the "proper" shorting.

    So my question boils down to:
    Even though it comes straight from the official manual of the very laptop I own, I'm still afraid of potential complications.
    What are the chances of a disaster and how safe is it and what tool would be better used for this task?

    Laptop model is Acer Aspire V3-771G

    Here's the manual in PDF form, you'll find the instructions I'm talking about in page 250 (PDF pages) or manual page 5-6.

    http://data.manualslib.com/pdf3/55/...?938780cbf246ab9d32913aa3e7ef2420&take=binary
     
  2. St1ckM4n

    St1ckM4n TS Evangelist Posts: 3,473   +622

    That's some odd instructions. Resetting BIOS is usually just removing all power sources: A/C; mobo battery; then shorting jumpers to expel any power in capacitors.
     
  3. Cobalt006

    Cobalt006 TS Maniac Posts: 1,851   +184

    If you are not sure about this. I would suggest you take it someone who service laptops. You could very well ended up with a dead motherboard.
     
  4. mteamix

    mteamix TS Rookie Topic Starter

    UPDATE:
    Past few days I've tried a number of things and found myself in a dead end.

    As far as I know there are 2 formal ways to reset bios.
    The one is to Short Jumpers and the other is to use Crisis Disk mode.

    I tried both and neither worked, although they are certain instructions that must be done in a correct order for these resets to work.
    In my case, both of the methods include the Power Button, holding it down and releasing in a very specific way.

    That doesn't work now because: My laptop opens as soon as I plug the AC in, it auto-starts, it turns on automatticaly just by pluggin in the AC cable.
    I google'd it and almost everyone attributes the problem to bad BIOS.
    The auto-start only started occuring after the earlier attempts to reset bios.
    My guess is that I messed the BIOS in the process of reseting the healthy BIOS.

    The story:

    0.Everything is fine.
    1.I explore bios, look around settings.
    2.I find "Default/Primary Screen/Monitor Display" or something along those lines and press enter to see other possible values for the option, there were 5-6 different ones.
    3.Moving away from that option I forgot which was the default value of the option so I put "auto" instead, thinking that is the holy grail of healthy curiosity.
    4.I exit BIOS saving the changes, that was the only change I had made, didn't see anything wrong with that.
    5.Upon restarting at that very instant, my screen turned black and unresponsive, it was obvious, my motherboard wasn't feeding power/data to my actual screen, a result of the options.
    6.I tried removing all batteries and AC for minutes, hours hoping for a bios reset but that didn't happen.
    7.I started searching on the internet and found that I had to short the jumpers for a proper hard reset, reached for the manual and there was a precise but for me dangerous practice of reseting bios, which I described in OP.
    8.My first attempts to short the jumpers weren't correct, which is when I think my BIOS got wrecked and the reason why laptop powers up when plugged in.
    9.Next day I tried both jumper shorting and USB CRISIS mode, although both of them required a certain way of pressing power button, it was that moment I first noticed the laptop was turning on automatically when plugged.
    10.The reset methods were impossible to recreate, because as soon as I plugged the AC in, I had also use Power Button in a certain way but pressing it would shut down the laptop, because it was already powered up.
    Recap:
    My initial mistake was capable of fully explaining the earlier symptoms.
    When I tried(half-assed) to reset BIOS, I made things worse by bricking BIOS.
    Which resulted in auto-start when plugged, which makes seemingly impossible to follow the correct sequence of reset methods.
    A paradox is created, to fix BIOS I have to fix the auto-power-up, to fix auto-power-up I have to fix BIOS, or at least this is how my limited range of knowledge perceives it.

    If you were in my place, with all your knowledge what would you do?

    I heard another option, keep the motherboard away from any power source for weeks so all the internal memory gets wiped out.
    Do you think this is possible? If so, how much time would it really need?
     
  5. Cobalt006

    Cobalt006 TS Maniac Posts: 1,851   +184

    You can try seeing if keeping it a way from power will work. But I have a feeling the mother board is bricked for good. I maybe wrong though. Anyway good luck with this.
     


Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...


Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.