Sony DCR-TRV738E Service Manual page 119

7. CAP FG Duty Adjustment (VC-278 board)
Set the Cap FG signal duty cycle to 50% to establish an appropriate
capstan servo. If deviated, the uneven rotation of capstan and noise
can occur in the Hi8/Standard8 LP mode.
Mode Playback
Signal Hi8/standard 8 alignment tape :
For checking operation
(WR5-5NSP (NTSC), WR5-5CSP (PAL) )
Measurement Point Pin qg of CN1108 (CAP FG)
Measuring Instrument Oscilloscope
Adjustment Page C
Adjustment Address 16
Specified value Duty = 50 ± 1 %
Note1: The data of page: 0, address: 10 must be "00".
Adjusting method:
Order Page Address Data
1
2 0 01 01
3 3 01 00
4 3 01 81
5 3 02
6 3 03
7
8 0 01 00
Note2: If the data of page: 3, address: 03 is other than "00", there are
errors. For the error contents, see the following table. (For the bit
values, refer to "5-4. SERVICE MODE", "4-3. 3. Bit value
discrimination".)
Bit value of page: 3, Error contents
address: 03
bit 0 = 1 Adjustment time-out
bit 1 = 1 Hi8/Standard8 mode wasn't set up.
Center of movement
A
B
Fig. 5-3-6.
Procedure
Set to the playback mode.
Set the data.
Set the data, and press PAUSE
button.
Set the data, and press PAUSE
button.
Check that the data changes from
"81" to "00".
Check that the data is "00".
(Note2)
Check that Duty of CAP FG signal
satisfies the specified value. If not,
repeat steps 3 to 7.
Set the data.
Duty = A/B × 100 [%]
DCR-TRV738E/TRV740/TRV740E/TRV840
5-53