North Star DIMENSION Service Manual page 60

TROUBLESHOOTING
Boot Problems (cont.)
Symptom Explanation
The computer
boots from
the diskette
drive but not
from the
fixed disk
drive.
Solution
1. Observe the lamps on the front panel of the fixed
disk drive while performing a boot from the
diskette drive . ( The front panel of the fixed disk
drive faces the rear of the central module. You
must remove the central module cover to observe
the front lamps. You may have to slide the drive
tower back.)
2. The lamps on a working Rodime 30 megabyte drive
flash on and off for approximately 15 seconds after
power on . Then they stay on . The lamps on a
defective drive flash a pattern of long and short
bits . Refer to the chart below.
Code Flash Pattern Explanation
1
Short - short - short-long
No index track data burst
2
Short - short - long-short
No flag zero
3
Short - short - long-long
Motor speed outside ±1 %
4 Short - long-short-short Motor speed outside ±10 %
5
Short - long-short-long
Flag zero always true
6
Short - long-long- short
Step received while gate true
7
Short - long- long-long
Write fault
8
Long- short - short-short
Not used
9
Long - short-short-long
Not used
10
Long- short-long-short
No index
11
Long- short - long-long Motor not up to speed
2-14 DIMENSION Service Manual