Switching Position Adjustment (Vc-235 Board); Agc Center Level Adjustment (Vc-235 Board) - Sony DCR-TRV820 Service Manual

3. Switching Position Adjustment (VC-235 board)

To obtain normal playback waveform output, adjust the switching
position.
Mode VTR playback
Digital8 alignment tape :
Signal
SW/OL standard (WR5-2D)
Measurement Point Display data of page: 3, address: 03
Measuring Instrument Adjustment remote commander
Adjustment Page C
Adjustment Address 10, 11, 12, 13
Specified Value 00
Adjusting method:
1) Insert the Digital8 SW/OL reference tape and enter the VTR
STOP mode.
2) Select page: 0, address: 01, and set data: 01.
3) Select page: 3, address: 21, and check that the data is "02".
Note: If the data of page: 3, address: 21 is other than "72",
the tape top being played. After playing the tape for 1
to 2 seconds, perform step 4) and higher.
If the data of page: 3, address: 21 is other than "62",
the tape end being played. After rewind the tape, per-
form step 4) and higher.
4) Select page: 3, address: 01, set data: 0D, and press the PAUSE
button of the adjustment remote commander.
5) Select page: 3, address: 02, wait data for stable condition as
"00".
6) Select page: 3, address: 03, and check that the data is "00".
Note: If bit 0 of page: 3, address: 03 data is "1", the A chan-
nel is defective. If bit 1 is "1", the B channel is defec-
tive. Contents of the defect is written into page: C, ad-
dresses: 10 and 12. See the following table. (For the bit
values, refer to "5-4. SERVICE MODE", "4-3. 3. Bit
value discrimination")
7) Select page: 0, address: 01, and set data: 00.
When the A channel is defective
Data of page: C,
Contents of defect
address: 10
Writing into EEPROM (IC4502) is
EE
defective
E8 Adjustment data is out of range
No data is returned from IC3301
E7
(CAIN)
When the B channel is defective
Data of page: C,
Contents of defect
address: 12
E8 Adjustment data is out of range
No data is returned from IC3301
E7
(CAIN)

4. AGC Center Level Adjustment (VC-235 board)

Mode
Subject
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note 1: Connect a 75 Ω resistor between Pin qh and Pin 6 (GND)
of CN259.
75 Ω resistor (Parts code: 1-247-804-11)
Note 2: Use a Hi8 MP tape.
Adjusting method:
1) Select page: 0, address: 01, and set data: 01.
2) Select page: 8, address: 2A, set data: C8, and press the PAUSE
button of the adjustment remote commander.
3) Record the camera signal for a minute.
4) Select page: 2, address: 2E, and set data: 01.
5) Playback the recorded segment.
6) Select page: 3, address: 33, and set data: 08.
7) Confirm that the playback RF signal is stable.
8) Select page: 3, address: 01, set data: 23, and press the PAUSE
button.
9) Select page: 3, address: 02, and check that the data is "00".
10) Select page: 3, address: 03, and check that the data is "00".
Note 3: If the data of page: 3, address: 03 is other than "00",
adjustment has errors.
11) Select page: 3, address: 33, and set data: 00.
12) Select page: 2, address: 2E, and set data: 00.
13) Select page: 8, address: 2A, set data: 00, and press the PAUSE
button.
14) Select page: 0, address: 01, and set data: 00.
Pin qh
Pin qd
5-45
Camera record and playback
Arbitrary
Pin qh of CN259 (RF MON) on
FU-141 board
(Note 1)
External trigger : Pin qd of CN259
(DV RF SWP) on FU-141 board
Oscilloscope
C
1E
The display data of page: 3, address:
03 is "00"
PB RF signal is stable
13.3 msec
Fig. 5-3-5