Undetermined Problems - Lenovo IdeaCentre B520e Hardware Maintenance Manual

• Checks the memory operation
• Starts the video operation
• Verifies that the boot drive is working
If the POST detects a problem, an error message appears on the screen. A single problem can cause several
error messages to appear. When you correct the cause of the first error message, the other error messages
probably will not appear on the screen the next time you turn on the system.
POST Error Message
CMOS Checksum Bad
System can not connect fan or fan modules are broken.

Undetermined problems

If this computer has a parallel ATA hard disk drive, make sure that the hard disk drive is jumpered as a
master and the optical drive is jumpered as a slave.
1. Power-off the computer.
2. Remove or disconnect the following components (if installed) one at a time.
a. External devices (modem, printer, or mouse)
b. Any adapters
c. Memory modules
d. Extended video memory
e. External Cache
f. External Cache RAM
g. Hard disk drive
h. Diskette drive
3. Power-on the computer to re-test the system.
4. Repeat steps 1 through 3 until you find the failing device or adapter.
If all devices and adapters have been removed, and the problem continues, replace the system board.
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IdeaCentre B520e Hardware Maintenance Manual
Description/Action
Checksum of CMOS is incorrect. The computer loads the
default configuration settings. This error might indicate
that CMOS has become corrupt due to a weak CMOS
battery.
Reseat the fan, or replace with known good modules.