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Old 08-08-2006, 06:41 PM   #1 (permalink)
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Default Warning 0251:System cmos checksum bad

i just bought a laptop recently(2wks ago) and when i turn it on on battery i get the black screen and a warning 0251:System cmos checksum bad- this is the second time it has happened both on booting up only on batteries, while if turned on ac adapter its normal.

is there a way to fix the corrupted cmos bios, or is better to changed the battery(even though its brand new)

oh ok

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Old 08-08-2006, 07:39 PM   #2 (permalink)
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Either your BIOS CMOS is corrupt or the battery for your BIOS CMOS has run out of power.

Since your laptop is operational, and that this only happens when running on the laptop battery, then it's most likely that your BIOS CMOS lithium battery needs replacing.

Your laptop manual should give you details on how to replace the lithium battery. Alternatively, the manufacturer's website usually provides laptop service manuals for users.

The battery is usually located underneeth the keyboard. Usually, you're required to pry out the keyboard to gain access. Otherwise, it should be on the underside underneath a removable panel.


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Old 08-08-2006, 07:45 PM   #3 (permalink)
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yup replace the motherboard cmos battery and your good also try flashing the bios.

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