Identifying parts on the system board, Identifying, Parts – Lenovo ThinkCentre M55 User Manual
Page 12: System, Board

Identifying
parts
on
the
system
board
The
system
board
(sometimes
called
the
planar
or
motherboard)
is
the
main
circuit
board
in
your
computer.
It
provides
basic
computer
functions
and
supports
a
variety
of
devices.
1
Diskette
drive
connector
13
PCI
Express
(x16)
graphics
adapter
connector
(some
models)
2
Speaker
connector
14
PCI
Express
(x1)
adapter
connector
3
Memory
connector
4
15
PCI
adapter
connector
1
4
Memory
connector
3
16
PCI
adapter
connector
2
5
Memory
connector
2
17
System
fan
connector
(not
used)
6
Memory
connector
1
18
Battery
7
Front
panel
I/O
connector
19
Temperature
sensor
connector
8
Serial
connector
(COM2)
20
Microprocessor
fan
connector
9
Serial
ATA
IDE
connectors
(5)
21
Microprocessor
10
Clear
CMOS/Recovery
jumper
22
Microprocessor
heat
sink
11
Cover
presence
switch
connector
23
12v
power
connector
12
Power
supply
connector
4
Hardware
Replacement
Guide