2500 XL  
(250-4074)                 Battery                    Faxback Doc. # 1147

Note: This cpu does not have a separate battery. Instead there is a
      real-time clock chip that maintains the system time and date. The
      clock chip includes an internal battery that powers the clock as well
      as system CMOS RAM. A record of your system configuration is stored 
      in CMOS RAM.

Use part number MX-1561 to replace the real-time clock chip

Note: The replacement part is available from National Parts

┌────────────────────┐
│Replacing the Chip: │
└────────────────────┘
The real-time clock chip battery should last at least three years with
normal use. When it fails, the computer will not retain time and date
information correctly.

When a configuration error is detected, the following prompt is displayed
when you turn on the computer:

    Invalid configuration information-please run Setup program

If the computer continues to display this message after you run Setup and 
update the configuration, it might indicate that the battery is weak or has
failed. 

To replace the real time clock chip, simply replace the chip at location U7
on the main logic board.

If you do not want to replace the clock yourself, a Radio Shack service 
technician will replace it for you.

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