Fixed Disk Problems - North Star DIMENSION Service Manual

TROUBLESHOOTING
Fixed Disk Problems
Symptom Explanation Solution
A newly 1.
installed
second fixed
disk drive
doesn ' t work.
2.
3.
Two flat cables ( signal and control) connect the
central board and the fixed disk drive/s. DC
power harnesses are also connected to the drives'
power inputs.
face up.)
The disk drive control cable ( wide flat cable) loops
first to the secondary disk drive ( on top) and
terminates at the primary disk drive (bottom).
The two signal cables must be correctly attached
to the central board--the primary drive signal
cable is attached the connector at the lead edge of
the board ( connector pins face the front of the
DIMENSION). The secondary drive signal cable is
attached to the inboard connector (connector pins
4. Only the primary drive uses a terminating resistor
pack ( because the final drive in a chain must be
terminated ). On HD15 ' s, the pack is a DIP (two
rows of pins like a normal IC) on the PC board,
facing out the bottom of the drive . On HD30's,
the pack is a SIP (one row of pins , like half an
IC) near the gold fingers ( peek inside to see it).
MAKE NO OTHER CHANGES TO THE DRIVE.
If the HD30 drive has any little wire jumpers
unhooked , rehook them (look near the terminating
resistor).
2-42 DIMENSION Service Manual