Service manual

56
8575
8575
A N/B Maintenance
A N/B Maintenance
Fan power PWM controlKeepOO1OTFAN ON#156P47/PWM1
Fan power PWM control
H
LH
LED indicator shift data
Hot key and battery dead beep sound
Thermal throttling control to
Southbridge
KeepOOOTLED DATA14P50/TXD0
Port 5 TTL input voltage (input high min=2V, input low max=0.8V)
System power on, need pull down to
define initial state during reset
KeepOOLOT↓H8 PWR ON49P40/TMCI0
LED indicator shift clock
External SMI# 5→3V
PS2 mouse IRQ12
Keyboard IRQ1
Need invert to SCI# sending to SB
5→3V/ Fan speed tachometer
SCI output and Fan Speed Tachometer
Switch
Function
Keep
Keep
Keep
Keep
Keep
Keep
Keep
Keep
Keep H
STANDBY
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
ON
1
0
0
H
L
O
O
O
O
O
O
O
O
O
After
RESET/OFF
T
T
T
T
T
T
T
T
T
During
RESET
LED CLK
H8 SMI#
FAN ON#0
Beep sound
ISA IRQ12
ISA IRQ1
H8 SCI/
FAN SPEED
SCI#/
FAN SPD SW
H8 THRM#
H8 Pin
Definitions
12
13
55
55
54
53
52
51
50
Pin
P52/SCK0
P51/RXD0
P46/PWM0
P46/PWM0
P45/TMRI1/HIRQ1
P44/TMCO1/HIRQ1
P43/TMCI1/HIRQ1
P42/TMRI0
P41/TMO0
Port 4 TTL input voltage (input high min=2V, input low max=0.8V)
Name
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