Electrical Adjustments - Sony FDL-3105 Service Manual

is- - 1. TV SECTION
PRECAUTION
1. Make adjustment in sequence as described.
Power supply voltage is + 9.0 + O.lV (DC jack end) unless
2.
otherwise specified. Power supply shall not be input
overlapped.
3. Check the error in waveform and screen for adjustment.
Measure a fluorescent tube and an liquid crystal display
4.
module device by connecting them with the A board.
5. Unless otherwise specified, input the color bar signal, etc.
from A/V IN jack (J301) by using AV-cord (AVK-715M,
etc.) to intercept the internal TV detection output. Also,
usually use monochromatic gradation wave mono scope
with chroma signal OFF.
6. Measuring instruments
NTSC pattern generator
l
Digital multitester
l
Oscilloscope
l
Frequency counter
l
Modes of Switches and Control
7 .
. . . .
l l
RV401 (VOL) . . . . . . . . . . . . . . ..minimum
VOLTAGE ADJUSTMENT
Procedure:
1. Connect a digital multitester between TP213 (+4.2V) and
(GND) on the A board, and then adjust RV602 so that
the reading of the voltage is + 4.2 t 0.02V.
Adjustment Location: A BOARD
WAVEFORM CHECK
H pulse check (H cycle)
Connect an oscilloscope to Pin 21 of IC301 (H PULSE) to
check if the waveform is as shown in the following figure.
(about 63.5 psec)
SECTION 3

ELECTRICAL ADJUSTMENTS

. . VHF
l l l
.
HORIZONTAL AFC ADJUSTMENT
Procedure:
1. Input the pattern generator (monoscope, '75 Q and
1 Vp-p) to the A/V IN jack (J301).
2. Short TP502 (IC801 pin 10) to GND.
3. The horizontal and vertical synchronization lines start
moving.
4. Adjust LV801 so that these lines stop moving.(Refer to
Figure 3- 2.)
Check that the frequency counter connected to TP505
5.
is 15.734 kHz + 60 Hz.
Disconnect the line between TP502 (IC801 pin 10) and
GND.
Check that the lines are in the display frame and the
7 .
synchronization is stable.
No good Good
Fig. 3- 1 Fig. 3-2
COMMON SIGNAL VOLTAGE ADJUSTMENT and HUE
C H E C K
Procedure:
1. input the pattern generator (Color chart, 75Q lVp-p) to
the A/V IN jack (J301).
2. Common signal check (2H cycle)
Connect an oscilloscope (DC) to TP513 (COM) to check
if the waveform is as shown in the following figure.
(63.5 p set)
3. Check that the blue signal output is as follows. (Chroma
demodulation)
If not, adjust RV306 (HUE Control).
These levels a r e almost the same.
No good
Fig. 3-3
GND electric potential