When it tried to restart it failed and flashed a message saying 'CMOS Bad checksum ddr2'. Using needle nose pliers, re-install the battery by pulling the negative terminal (flat side) out enough to slide the battery in at a diagonal. I was using my desktop today and went to login after I started it and the computer crashed and restarted.This occurs when your system is below BIOS level 50KT45A and you flash it to 50KT45A or higher. You have to tilt it slightly towards the processor then lift it out. Symptom 'CMOS Checksum Bad' appears on the screen at the end of POST and BIOS configuration settings are lost after flashing the BIOS. Using needle nose pliers remove the battery.If its under 50 of the design capacity, it will drain very rapidly. It will tell you how much of the batterys initial capacity remains. You can run a battery report: Open a command prompt with admin privileges, and type powercfg /batteryreport. With your finger nail, gently pull back the negative terminal pressing against the flat side of the battery. Dont count on the 'battery health' meter - its not a reliable measure.Also, verify the date and time are correct. If the error still occurs after rebooting the computer, enter CMOS setup and check all values.

Bad or old CMOS battery Reboot the computer. otherwise from 2 months when I switch on the laptop the laptop fails to boot and the system do not proceed from the post screen. If you encounter a CMOS checksum error on your computer, the following steps may help you fix the problem. the message comes once in 10 times I open the laptop. Place the controller on a table, hard drive side down. 0251 : SYSTEM CMOS CHECKSUM BAD LOADING THE DEFAULT CONFIGURATION.To replace the battery yourself, follow the instructions below: The CMOS memory stores a specific value normally to guard the. If the problem persists, replace the RTC battery. The CMOS Checksum Bad Error is an error that occurs when the CMOS values turn out to be incorrect. Before you replace the battery, make sure you inspect the controller to make sure that the metal clip is making contact with the battery, the battery edges are not corroded, and that there is no physical damage to the controller. CMOS checksum is bad, possibly because the system was reset during BIOS boot or because of a dead RTC battery. Additional InformationYou may replace the battery (BR2032 3V Battery) yourself, though National Instruments will not be responsible for any damage to the controller.

System cmos checksum bad