Bose 3-2-1 Service Manual

11
Preliminary
4. DVD Drive Replacement
4.1 Install the two Phillips-head screws (6)
that were removed in step 3.5. These screws
should be installed into the two threaded
holes located on the underside of the drive
(5) near the front. These screws will protrude
from the chassis of the drive and are used to
help align the drive with the console casting
(14).
4.2 On the rear of the DVD drive, plug in the
ATAPI (8) cable and power (7) cables. Be
sure that the strain relief on the ATAPI cable
is on the end...

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Preliminary
Note: To assure correct clamping, you
should use a new DVD clamp when installing
the DVD drive into the console.
4.8 Align the clamp (3) over the DVD drive
(5) and with the ears of the casting (14).
Press down firmly on the clamp until it snaps
into place on the casting.
4.9 Place the drawer opening in the bezel
sub assembly (27) over the DVD drive
drawer, allowing the drawer to extend
through the opening. Align the slots in the
DVD drawer bezel (28) with the DVD drawer.
Slide the DVD...

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Preliminary
6.5 Align the I/O panel (19) with the connec-
tors on the main PCB. Press the I/O panel in
place on the console base (21). It should
snap in place and be flush with the base all
around its perimeter.
6.6 Perform procedure 4.
7. LCD Display PCB Removal
7.1 Perform procedure 3.
7.2 On the main PCB (20), unplug the ribbon
cable at connector J6500. This cable runs
to the LCD display PCB (26). Peel off the foil
ground strap (25) located directly under the
ribbon cable. This foil strap provides...

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Preliminary
  Disassembly/Assembly Procedures
  (continued)
Array Procedures (continued):
1.2 Place the array on its back on a bench.
Use your thumb to press down on the array
grille just where at the top of the curve. At
the same time, use the screwdriver to pry
the end of the grille off of the array housing.
It should come free of the housing. Repeat
this step at the other end of the grille. Lift the
grille off the housing.
2. Grille Replacement
2.1 Align the grille so that the Bose
® logo is
facing...

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Preliminary




4.4 Apply a 250 mV, 1 kHz signal to the
analog input of the SPDIF converter.
4.5 On the console, select the VIDEO 1
source.
4.6 Measure the output level at the line
outputs on the console rear panel. It should
be 250 mVrms 
+ 10%.
5. Video Tests
5.1 Connect the video generator to the
COMPOSITE VIDEO  INPUT  only.
5.2 Connect the video monitor to the COM-
POSITE  VIDEO  OUTPUT.
5.3 Set the video generator to display a test
pattern.
5.4 On the console, select the VIDEO 1...

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Preliminary
Figure 2. Laser voltage test points
Figure 3. Laser current rating label
8.3 Insert the ABEX TCD-714R test disc
into the console CD/DVD tray. Play the
defect  tracking  (eccentric  disc)  track. Verify
that the disc plays properly. The nominal is a
280 um defect, 210 um limit.
8.4 Insert the ABEX TCD-732R test disc
into the console CD/DVD tray. Play the
defect  tracking  (warped  disc)  track. Verify
that the disc plays properly. The nominal is a
1.0 mm defect, 0.7 mm limit.
8.5 Insert the...

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Preliminary




 3-2-1 Console Tuner Adjustments/
Measurements
The following tests can be performed without
the use Of An IBM compatible PC
Set up the device under test (console) as
shown in the diagram below.
Figure 4. AM Loop Antenna Test Setup
AM Adjustments
For all AM alignments and tests plug the AM
antenna, part number 199824-002, into the
console and position it at least 2 feet away
from the unit. Configure the AM antenna, a
standard test loop and RF generator as
shown below to...

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To find the required setting in dBuV emf from
a given dBf value for an RF generator with a
50 ohm output impedance use the conver-
sions given below.
Note: For generators with RF level resolution
of only 1dB round up.
12. FM Distortion Measurement/Adjustment
12.1 Inject a 98.1MHz RF signal at a level of
65dBf into J2000.
12.2 Tune the console to 98.1MHz.
12.3 Measure the distortion plus noise
(THD+N) at the tape output. If it is less
than or equal to 0.50%, verify that the...

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Note: If you receive an error response on
the computer screen, enter the TUAM com-
mand to ensure the correct mode is selected
and re-enter the command in 15.2.
To verify the AM tuning frequency enter the
TUGF command to get the presently tuned
frequency. The response on the computer
screen should be  “1500“ followed by an
“ACK>”
15.4 Adjust the red slug of T2004 for maxi-
mum audio output. Verify that the level is
greater than 40 mVrms.
15.5 Inject a 600kHz RF signal at a...

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17.4 Enter the command TUIF into the
computer. The unit will then go through an
algorithm that determines the optimum offset
for the local oscillator (L.O.) setting to ac-
count for filter variances in the IF strip. This
offset is then stored in the EEPROM.
Enter the command TUGI to see the stored
offset; the response on the computer should
be as follows: “TUGI    X >” followed by an
“ACK>” (where X is the stored offset).  The
actual frequency offset of the L.O. is this...