Fuses And Polyswitches (Resettable Fuses); Table 3-3. Fuse Assignments - Motorola MCP750 Installation And Use Manual

Functional Description
3

Fuses and Polyswitches (Resettable Fuses)

Fuse#
F1* Slow
Blow
F2* Slow
Blow
F3* Slow
Blow
R18 Poly-
switch
R20 Poly-
switch
3-18
(DS1, yellow). Board Failure; lights when the
BFL
line is active.
(DS2, green). CPU activity; lights when the
CPU
Busy) signal line on the processor bus is active.
(DS4, green). PCI activity; lights when the
PCI
Ready) signal line on the PCI bus is active. This indicates that the
local PCI bus is active.
(DS3, green). CPCI activity; lights when the
CPCI
Ready) signal line on the CPCI bus is active. This indicates that the
CPCI bus is active.
The MCP750 provides inline slow-blow fuses for each power rail
including +5Vdc, +3.3Vdc, and PMC +5Vdc. Polyswitches are provided
for VIO, keyboard/mouse Vcc, and the two USB output voltages, +12Vdc
and -12Vdc. The Table 3-3

Table 3-3. Fuse Assignments

Type Voltage/Purpose/J Number
+3.3Vdc for onboard voltage, to J12 PMC connector
and to J3/J4 Transition module connectors
+5Vdc for onboard voltage and to J3/J4/J5 Transition
module connectors
+5Vdc to J11/J13 PMC connectors
+5Vdc to J5 Transition module connector for
keyboard/mouse voltage
+12Vdc to J12 PMC connector and J3 Transition
module connector
lists the fuses with the voltages they protect.
Computer Group Literature Center Web Site
signal
BRDFAIL
(Data Bus
DBB
(Initiator
IRDY
(Initiator
IRDY
Fuse
Rating
5A
5A
2.5A
1.1A
2A