reset cmos battery without unsoldering?

By chessonly
May 18, 2007
  1. I have a Toshiba laptop which decided to setup a bios-password , for who knows why..

    After many scratches (both on the laptop and on my hands) I managed to disassemble the laptop, to remove the cmos battery.
    Now I can see the cmos battery soldered into the laptop. 2 small wires that are connected to the +ve and negative sides of the battery are soldered to the mobo.

    Is there an alternative to unsoldering the battery. I don't have any experience with soldering and would like to try safer alternatives, if any, before I have to try unsoldering. Is it possible to shot the battery or do something else that would reset the bios?


    Oh and I have searched like crazy for 'software' solutions and master passwords but can't find anything that worked.
    Laptop -Toshiba satellite a135-s2276
  2. raybay

    raybay TS Evangelist Posts: 7,241   +9

    Cut the wires, then reconnect them later... even if you have to insert a length of wire... but learn to solder asap.
  3. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

    generally there is a jumper next to the CMOS battery. If not, you will have no choice.
  4. raybay

    raybay TS Evangelist Posts: 7,241   +9

    Rare on most Toshiba laptops.
  5. chessonly

    chessonly TS Rookie Topic Starter Posts: 40

    I haven't fully disassembled the laptop yet, so cutting the wires isn't an option (yet)..
    there are no jumpers. You would think that toshiba doesn'teven know their laptop has a problem, but as a fact this problem (spontaneous bios password) is atleast 9 months.

    Will the PC boot without a cmos battery?
  6. CCT

    CCT TS Evangelist Posts: 2,653   +6

    I read where a possible default bios password was Toshiba - did you try that?
  7. raybay

    raybay TS Evangelist Posts: 7,241   +9

    Have you ever talked to Toshiba tech support? If you are the registered owner, they may fix the password for a $65 fee.
    Of course it will not boot without a CMOS battery.
    What you are describing is extremely hard to do... almost impossible to make this happen, unless by a spurious electrical response. The password is entered into an EEPROM into digits provided...
    Is there any chance at all that somebody got their hands on your Toshiba, and either as a joke, maliciousness, or stoopid diddling, created a password.
    In addition, try other passwords besides TOSHIBA, then SATELLITE or TECRA, model name, serial number.
  8. chessonly

    chessonly TS Rookie Topic Starter Posts: 40

    The whole problem is that I am in India, while the laptop was bought from US. I could send it to US in november and get it fixed under warranty. But that a long way off.

    My desktop does so :)

    What happened..
    I booted pc > attached a USb to serial adapter > pc froze > did a hard-reset > rebooted. Now it asked for a password.

    Turns out its an known problem with toshiba notebooks.

    My problem is solved :) :), in a way...

    The alternative to unsoldering being 'twist battery till metal soldered to motherboard breaks' . I know its crude but it worked.
    A friend offered to solder it back, back after watching a soldering iron , I am not letting something that hot get anywhere near my mobo. So I just taped it the battery to the mobo.
    Ofcourse I didn't expect it to hold and it doesn't,
    but but..

    The good thing is that the laptop still boots just fine! and most importantly the main li-ion battery does the job of the cmos battery!!! So if the problem reoccurs all I'll have to do is remove the main battery! and the bios will be reset.
    ahhhhhhhhh haaaaaah

    Thanks to all who replied
  9. sw123

    sw123 TS Rookie Posts: 595

    Good thing your problem is solved. Stupid Japanese manufactuerers.
  10. LinkedKube

    LinkedKube TechSpot Project Baby Posts: 3,481   +44

    Toshiba wont help you once you told them you took the pc apart, lol. I have one of their sattelite models. Took it apart, all bad, ha
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