Lexmark T640 Service Manual page 306

4061-xx0
System board (see "System board" on page
Connector
J27 LVPS (continued)
J28 MPF paper out
J29 Top options
J30 USB host–back
USB host—front connection
Printhead fan
5-6
Service Manual
5-1)
Pin no. Signal
17 HEAT
18 HEAT
19 Ground
20 L FAN DRV*
1 MPF POUT
2 Ground
3 MPF LED
1 RXD1R
2 Ground
3 TXD1BR
4 Ground
1
2
3
4
5
6
7
1 +5 V USBICN
2 USB DI–
3 USB DI+
4 Ground
5 Ground
1 +24V dc
2 PH FAN*