HP 7942 Service Manual page 132

Backdating Information
7942 and 7946
on HDC FRAS (6) to the rear panel of the
mainframe assembly (S I).
i. Disconnect connector Pion cable assembly W2
(30) from connector
J1
on HOC FRAS
(6)
and
slide FRAS forward approximately three inches.
j.
Loosen the T I 0 screw (36) which secures disc
drive assembly UO-FRA I
(3S)
to the interior of
the mainframe assembly (51), adjacent to the
fan (31). It is not necessary to remove this screw.
h. Slide disc drive assembly UO-FRAI (35) forward
and out of the drive.
Note: Disc drive assembly UO-FRAI (3S)
is replaced as a unit and no further
disassembly is required.
Reinstallation is a reversal of the removal proce-
dure. Ensure that the cable assembly connectors
disconnected in steps d, e, and i are firmly seated in
their mating connectors.
AS-IZ. UO-FRAZ (DISC DRIVE DOC PCA-AZ)
To remove disc drive DOC UO-FRA2 (49), proceed
as follows:
a. Perform the preparation for service procedure
outlined in paragraph AS-2.
b. Ensure that the power cord is disconnected from
the .., AC LINE connector on the rear panel of
the drive.
c. R.emove the top shroud (refer to paragraph
A5-4) and the front panel (refer to paragraph
A5-7).
d. Disconnect connector P3 on power cable assemb-
ly WI (38) from connutor JI on disc drive DOC
UO-FRA2 (49).
e. Disconnect connectors PI and P2 on ribbon cable
assembly
W
3 (37) from connectors
J 3
and
J
4,
respectively, on disc drive DOC UO-FRA2 (49).
f. Disconnect conllector Pion LED cable assembly
W 4 (12) from connector J 5 on disc drive DOC
UO-FRA2 (49).
g. Remove the T 10 screw (29) which secures cover
plate (28) to the rear panel of the mainframe as-
sembly (51) and remove the cover plate.
AS-6
h. Disconnect connector P2 on cable assembly W2
(30) from connector J2 on disc drive DOC
UO-FRA2 (49).
i. Carefully slide disc drive DOC UO-FRA2 (49)
forward and out of the drive.
Reinstallation is a reversal of the removal prace-
dure. Before installing disc drive DOC UO-FRA2
in the drive, ensure that switch U484 is set as fol-
lows. Refer to figure 4-10 for the location of
U 4 8 4. Ensure also that the cable connectors dis-
connected in steps d through f and h are properly
seated in their mating connectors.
HP 7942
HP
7946
1
- closed
1
- closed
2 - open (up) 2 - open (up)
3
- open (up)
3
- closed
4 - open (up) 4 - open (up)
A5-13. UI-FRAZ (TAPE DRIVE DOC PCA-AZ)
To remove tape drive DOC UI-FRA2 (SO), proceed
as follows:
a. Perform the preparation for service procedure
outlined in paragraph A5-2.
b. Ensure that the power cord is disconnected from
the .., AC LINE connector on the rear panel of
the drive.
c. Remove the top shroud (refer to paragraph
A5-4) and the front panel (refer to paragraph
A5-7).
d. Disconnect connector P7 on power cable assemb-
ly WI (38) from connector J4 on tape drive
DOC UI-FRA2 (SO).
e. Disconnect connector P2 on cable assembly
W
5
(1 7) from connector J 3 on tape drive DOC
U I-FRA2 (SO).
f. Remove the TIO screw (29) which secures cover
plate (28) to the rear panel of the mainframe as-
sembly (51) and remove the cover plate.
g.
Disconnect connector P 3 on cable assembly W 2
(30) from connector J 1 on tape drive DDC
Ui-FRA2 (SO).
h. Disconnect connector Pion ribbon assembly W 6
(27) from connector J2 on tape drive DOC