Technical data

Fault Isolation 4-45
Table 4-9. System Unit LED Failure Codes (Cont.)
LEDs State or Failure LEDs State or Failure LEDs State or Failure
Failure:
ROM system.
Replace ROM
system.
Failure:
Boot error.
Replace CPU
board.
Failure:
Operating system tried
to load at too high of a
memory address.
Try again or replace CPU
or emulator board.
Not enough memory
to load operating
system.
Add more memory.
Failure:
4 MS timer.
Replace CPU
board.
Failure:
HP-HIL circuit.
Replace CPU
board.
Failure:
HP-IB board.
Replace HP-IB
board.
Failure:
DMA circuit.
Replace CPU
board.
Failure:
High-resolution
video board font
ROM.
Replace video board.
Failure:
Video board
bit-map circuit.
Replace video board.
Failure: DIO-I Interface
at select code identified
by five lowest LEDs.
Replace board that has
the failed interface.
Failure: DIO-II Interface
at select code identified
by five lowest LEDs.
Replace board that has
the failed interface.
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H
A
B
C
D
E
F
G
H