Service manual

PN 4237242C
4.6-3
SERVICE AND REPAIR PROCEDURES
AT MOTHERBOARD
4
Verification
Without a keyboard and monitor the best way to verify AT motherboard operation is to use
the instrument.
1. Turn ON the instrument’s power and check to see that the system reaches the Main
Menu. This tells you that you have successfully:
r Passed BIOS POST
r Booted
r Read from the floppy disk drive
r Executed a program
r Communicated with all four cards plugged into the bus.
Figure 4.6-2 AT Motherboard
W3
(1-2, 3-4)
J15 SER1 J14 SER2
J17 FLOPPY
J18 PARALLEL
P8
P9
SW1
J19
EXT BATT
BATTERY
J20 IDE
BANK 0 BANK 1 BANK 2 BANK 3
W3
NYLON
MOUNTING
POST(8)
CC MD V1.0
GROUND
SCREW
J21
(Reset)
J22
(Speaker)
J23
(Keylock)
J24
(IDE
activity)
J25
(Turbo
LED)
J26
(Turbo
SW)
7242009A
J17
(Floppy disk
drive)
J18
(Parallel printer
port)
SW1
GROUND
SCREW
J15
(Serial 1 port)
J14
(Serial 2 port)