Question about Toshiba Satellite A100-S8111TD Notebook

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0251: System CMOS checksum bad-Whats this? ToshibaA105-S4254

Dear All,
I have a 2 yr old Toshiba A105-S4254.No software problems so far (except for the power chord problem, now solved, which is pasted below). But,today For the fist time when I turn the power switch on I get a black screen and I get this message (among other things that are written):

0251: System CMOS checksum bad- Default configuration usedPress to load default to set up"

I have no idea what this is. Which of the two F1 or F2 should I press?
Thanks in advance,
PS: I have pasted the old probem which got solved last week below just in case it is related to this current one. Thanks

PREVIOUS PROBLEM that got magically solved on its own is given below:

Dear All,

Ironically, 5 days after the paid warrenty expired (2 years and 5 days after I bought this piece of equipment), the A105-4254, it suddenly died on me!

It always had a "loose connection" to the AC adaptor. While working at home, I always had to pull and yank the power cable everytime I used it to make sure the "blue power light is on" and that power is being supplied to my laptop or else it would indicate that it is being powered through the battery instead.I lived with it. However around Christmas, when it was the season to be Jolly, the power cable connection started acting up big time and I perpetually had to hold the powersupply cable connection to the laptop with my left hand and type using only one hand. This went on for a few days. And then, on January 17 2009, my laptop just died on me. Like dead dead.I bought a new powercord ($150)- nothing. I removed the battery and plugged in the AC adapter-nothing. No lights, no sounds, nothing. I cannot live without my laptop. Help.

Please give some suggestion which do not include paying an arm and a leg to get it repaired (it is outside the warrenty remember).
Thanks to all in advance,

Posted by on

  • shr8002 Jan 28, 2009

    Thanks DJSam. I will press F1 as you recommended.

    What exactly is CMOS?

    And I didn't do anything to my laptop in ternms of software, so then how did the "checksum" become "bad"? In other words, what could I have done to cause this? I only use my computer (toshipa laptop) to surf the internet and check emails etc.

    Thanks again,


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You can go ahead and press F1. If it happens again the next time you boot up or it just goes back to that screen try pressing F2 and then exit with saving.

This should solve your problems, If it doesnt you have something configured incorrectly in the CMOS.

If this is the case there should be somewhere that you can restore the defaults of the CMOS (as every computer is different I can't guide you through this process)

Have a great day.

Posted on Jan 28, 2009

  • djsam112 Jan 28, 2009

    CMOS - complementary metal-oxide semiconductor

    It is the chip that holds all of the information for the BIOS.

    It is basically the base workings of the computer on how it runs all the hardware.

    I apologise for neglecting to state this in my last response but if it keeps happening this could be due to your internal battery (looks almost like a watch battery) going dead.

    Another thing that can cause this is a faulty BIOS install or a program that changes settings in your BIOS. As updating the BIOS can be a risky procedure i would recomend getting someone confident in this to do it for you. (Do this only if it is the problem)

    So again if this keeps happening it is most likely the internal battery that powers the CMOS chip as you have already stated that it is most likely not due to software.


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SOURCE: A105-S4254 is dead!

According of your description, If you already changed the power suply, and the battery, and still no signs to power on, your laptop has some issue at power connector in the motherboard and need to be serviced.

Posted on Jan 24, 2009

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