JVC HR-S6970AA Service Manual page 14

(4) Transmit the code (F) from the Jig RCU to adjust so that the
noise bar becomes the specified value (G) on the TV
monitor in the slow mode.
(5) Set the VCR to the Stop mode.
(6) Confirm that the noise bar is (G) on the TV monitor in the
slow mode.
(7) Repeat steps (3) to (6) in the REV slow (+1/6x) mode.
(8) Repeat steps (1) to (7) in the mode (B2).
(9) Record the signal (A3) in the mode (B1), and play back the
recorded signal.
(10) Repeat steps (2) to (8).
Note:
• For FWD slow (+1/6x) playback, transmit the code "43-
08" from the Jig RCU to enter the slow playback mode,
and transmit the code "43-D0"for REV slow (-1/6x)
mode.
4.3.2 Video circuit
4.3.2.1 EE Y/PB Y level
Signal (A1) • Ext. S-input
(A2) • Ext. input
(A3) • Color (colour) bar signal [PAL]
(A4) • Color (colour) bar signal [NTSC]
Mode (B1) • EE SP
(B2) • S-VHS SP
(B3) • VHS SP
Equipment (C) • Oscilloscope
Measuring point (D) • Y OUT terminal (75 ohm terminated)
EVR mode (F1) • Jig code "43-57"
EVR address (F2) • A : 11
(F3) • Jig code "43-21" twice
(F4) • Jig code "43-18" or 43-19" (Channel +/-)
Specified value (G) • 1.00 ± 0.05 Vp-p
Adjustment tool (H) • Jig RCU [PTU94023B]
(1) Input the signal (A3) from the input point (A1).
(2) Set the VCR to the mode (B1).
(3) Observe the Y OUT waveform at the measuring point (D).
(4) Set the VCR to the EVR mode by transmitting the code (F1)
from the Jig RCU.
(5) Set the EVR address to (F2) by transmitting the code (F3)
from the Jig RCU.
(6) Transmit the code (F4) from the Jig RCU to adjust so that
the Y level of the Y OUT waveform becomes the specified
value (G).
(7) Release the EVR mode of the VCR by transmitting the
code (F1) from the Jig RCU again. (When the EVR mode
is released, the adjusted data is memorized.)
(8) Input the signal (A3) from the input point (A2).
(9) Repeat steps (3) to (7) in the mode (B1).
(10) Record the signal (A3) in the mode (B2), and play back the
recorded signal.
(11) Set the VCR to the manual tracking mode.
(12) Repeat steps (3) to (7) in the mode (B2).
(13) Record the signal (A3) in the mode (B3), and play back the
recorded signal.
(14) Set the VCR to the manual tracking mode.
(15) Repeat steps (3) to (7) in the mode (B3).
(16) Input the signal (A4) from the input point (A1).
(17) Repeat steps (2) to (15).
1-14 (No.YD047)
H. rate
Fig.4-3b EE Y/PB Y lebel
4.3.3 Syscon circuit
Notes:
• When perform this adjustment, remove the Mechanism
assembly.
4.3.3.1 Timer clock
Signal (A1) • No signal
Mode (B) • EE
Equipment (C) • Frequency counter
Measuring point (D1) • IC3001 pin 44
(D2) • IC3001 pin 103
(D3) • C3054 + and -
Adjustment part (F) • C3025 (TIMER CLOCK)
Specified value (G) • 1024.008 ± 0.001 Hz
(976.5549 ± 0.0010 usec)
(1) Connect the frequency counter to the measuring point
(D1).
(2) Connect the short wire between the short point (D2) and
Vcc (5V).
(3) Short the leads of capacitor (D3) once in order to reset
the microprocessor of the Syscon.
(4) Disconnect the short wire between the short point (D2)
and Vcc then connect it again.
(5) Adjust the Adjustment part (F) so that the output frequency
becomes the specified value (G).
Y level